Acts of Stupidity by Character

Much of the deaths that occur in Happy Tree Friends are a result of the main characters doing something ignorant, unwise, or downright stupid. Almost every character is prone to committing these actions, causing the deaths of themselves and/or others around them.

Cuddles
Cuddles is known for being mischievous and self-centered, which is often the root cause for his actions.
 * Water You Wading For: Cuddles jumps into a lake despite that swimming is forbidden, which Flaky points to. Because of this, Cuddles is attacked by creatures in the lake and crushed by a whale.

Giggles
Like most characters, Giggles is blissful and unaware of hazards until the last minute.
 * Better Off Bread: Giggles skips through flowers until, not watching where he was going, she falls off a cliff.

Lumpy
Lumpy is considered the least intelligent character in the series and is responsible for the majority of these acts. While famous for getting others killed, his stupidity goes further to the point where he can be seen as retarded.
 * Spin Fun Knowin' Ya: Spins the merry-go-round so hard it causes Cuddles, Toothy, and Giggles to fly off. In his defense, they did keep telling him to spin faster.
 * Wheelin' and Dealin': Wears a snorkel and scuba mask in a cart race.
 * Treasure Those Idol Moments: Runs over Flaky in clear sight. This was caused by the Idol, though, so it doesn't count.
 * Dunce Upon a Time: Sticks a fork in a plugged in toaster 3 times. Though he was simply after Flaky and didn't seem effected much by the electrocution.
 * You're Bakin' Me Crazy: Brings Petunia a blood-covered cake and stupidly says "Merry Christmas!" at her birthday party.
 * Meat Me for Lunch: Doesn't care at all that Lifty & Shifty were killed, and used their remains to make meat for his butcher's shop. (debatable, as Lumpy not caring that the raccoons were killed and feeding them to his customers simply showed his vengeful side; However, he looks surprised when Petunia realizes she's eating someone).
 * It's a Snap: Falls for bear traps baited with cheese.
 * Snow What? That's What!: Lies shirtless on a hammock with a drink... in the winter. Although to be fair, he doesn't seem to be shivering or showing signs of hypothermia.
 * Happy Trails Pt. 1: Isn't paying attention to the road (even walking away from the wheel), causing a crash on a stranded island. To be fair, Petunia and Mime took his attention away from the road.
 * Class Act: Instructs Toothy to go on with his act despite the other play actors' injuries. Also casts Nutty in a play that has a character dressed as a candy cane.
 * Rink Hijinks: Wearing skis at a rollerskating rink.
 * The Way You Make Me Wheel: Shaves while driving, resulting in his death and Handy's death as well.
 * I Get a Trick Out of You: Unintentionally suffocates a bird by keeping it in his hat, saws Cuddles' in half due to a magic trick, and later uses up the blood which Cuddles needed to survive.
 * Icy You: Somehow gets his tongue stuck in hot dog rollers and keeps working with his tongue stuck.
 * Out on a Limb: Cuts off the leg which wasn't stuck under the tree instead of vice versa.
 * Remains to be Seen: Chooses a leaf blower over a chainsaw to kill the zombies. But since Lumpy successfully defeated Flippy with said leaf blower, it really isn't stupid at all. But, considering the situation and Lumpy's luck, the chainsaw would have been a better choice. Though also given Lumpy's luck, he would have likely cut off his own limbs with the chainsaw and even if he didn't, it would have taken much longer to defeat all of the zombies.
 * From A to Zoo: Puts in a dart the wrong direction, causing it to go down his throat and tranquilizes himself (he was doing this carelessly because he was in panic, however, not stupidly). He also doesn't notice a rhino's horn obviously went through Toothy's head, and mistakes a baboon for Sniffles (or just doesn't care).
 * The Wrong Side of the Tracks: Designs a roller coaster so poorly that it causes the deaths of the riders and himself. He also nails a wooden board to his ride with Mime impaled to it.
 * Don't Yank My Chain: Falls for Lifty & Shifty's foolish disguises and arrests Handy and Mole. Leaves the cell open with the keys near it. Takes several seconds to realize that Handy and Mole had gotten away. Uses part of Mole's sweater (a clue to finding them) to blow his nose.
 * Doggone It: Blows a whistle and causes puppies to attack him. Assuming that only that Whistle would go berserk, and not all of the look-alikes, is not particularly stupid. If only Whistle goes berserk, it would be a sensible way of distinguishing him from the others, as Lumpy felt he could handle one Whistle and really he had no reason to suspect that all of the dogs would go berserk.
 * Concrete Solution: Makes a bridge out of sugar instead of cement. To be fair, who would have expected a bag of sugar mixed in with a bag of cement, especially as their bags have the same color, shape and size? Probably more of carelessness than stupidity, and he did complete the bridge alone after Handy and Mole were killed, and would have been successful if not for Nutty). The real act of stupidity in this episode is looking inside the nail gun and firing it. He was lucky it wasn't plugged in.
 * Wishy Washy: He was walking in with his shoes dirty, Then exited and came back in only to realize that there is a mat underneath him, And when Petunia chokes on a glove, Lumpy puts his plunger into Petunia's mouth in order to help her.
 * Who's to Flame: Foolishly plays with a lit match, which is ironic considering his fireman job (Not particularly stupid, because he's playing it in such a way that won't cause disasters).
 * Every Litter Bit Hurts: Destroys an entire tree just to make one toothpick (Though this was just to show how much of an a-hole he is in this episode) and clogged his exhaust pipe with a pine cone.
 * As You Wish: He also sets Cub on fire and gets him run over by a firetruck. To be fair, it really depended on how Pop worded his wish, as Lumpy was able to successfully grant Nutty, Disco Bear and Sniffles' wishes.
 * Take a Hike: Dunks Sniffles in a river with sharp rocks, piercing his head repeatedly, though to be fair, he had no way of knowing what was under the water in that one spot. Uses up all the drinking water for shaving instead of that in the lake. Doesn't look after the group well enough. Takes a nearly broken bridge over a strong one (though this was out of fear, so he wasn't paying attention).
 * A Change of Heart: Lumpy repeatedly losing the normal sized hearts due to his not paying attention. However, he did successfully implant a whale heart on a bear with Disco Bear surviving, and knew that using a bicycle pump would keep Disco Bear alive, so even if it looks stupid, it was probably not.
 * Blast from the Past: Pushes his body so hard on a seesaw that the handle impales him. Laterrepeats his stupid acts that he did in "Spin Fun Knowin' Ya!".
 * Chew Said a Mouthful: Mistakes a jawbreaker for Toothy's eye and draws a pupil on it and puts it in Toothy's eye socket, also drawing a mustache on him.
 * Idol Curiosity: Mistakes ice in Toothy's drink for an iceberg. This was caused by the Idol, though, so it doesn't count.
 * Home Is Where the Hurt Is: Folds the blueprints of Giggles' new house into a origami crane. Later, he connects electrical pipes to normal pipes for the shower, which electrocutes Petunia later.
 * Aw Shucks!: Unintentionally destroyed his house while trying to kill a crow, and thought Toothy's corpse was his scare-crow. Although to be fair, Lumpy might have known it was Toothy, but simply did not care as long as he could serve as a scarecrow.
 * Wingin' It: Uses many electronics, despite Mime telling him not too. Later, he takes all five parachutes simply meant that he did not care for his fellow passengers, not particularly stupid. What is stupid is his failure to properly wear even one of these parachutes properly so in the end, it didn't save him.
 * Tongue in Cheek: Mistakes the skin from Sniffles' hand as his glove and his organs as a mini-golf course. Although he could have known it was Sniffles' hand and his organs, but he just didn't care as long as he had fun playing golf. Though, anyone who plays golf knows that you only wear one glove so he shouldn't have been looking for the other glove in the first place.
 * I've Got You Under My Skin: Tries to stop Sniffles from traveling further up his body, but ends up severing his leg. He is also shown to have numerous strange items, including a plane propeller and a bear trap, inside his pockets.
 * Junk in the Trunk: Takes forever to compare the elephant in Lifty & Shifty's car and the one he put on his missing elephant poster. He also chooses a pogo stick over a race car to chase after the thieves. Although to be fair, he was successful in chasing the twins with the pogo stick, so that was not particularly stupid also, if he had chosen the race car, he would have had to get far enough AHEAD of them, pull off, get out, and find a way into the speeding van on foot where the pogo stick allowed him to bounce straight into the van wasting no time.
 * Hear Today, Gone Tomorrow: Doesn't realize his can was on his butt and ran to get some new things. He later tries to use a trombone as a hearing aid, tries to phone the hospital while deaf, wears a birthday hat the wrong way (though it was likely simply a difficult task to get it around his antlers), and tries to phone for help using a can telephone.
 * Double Whammy Part 1 and 2: Hypnotizes himself, making him act like a chicken. This is later seen in part 2, where he is inside a chicken truck trying to lay eggs. Also, in Part 1, he shows Flippy ink blobs that even to a normal person look like: a dagger, a bomb, and an explosion causing him to flip out. (Though this could have been done as a way to test what causes the flip outs).
 * Can't Stop Coffin: Buries what was originally an empty coffin, fills the hole with water (though this could have been done to extinguish the fire), and leaves his truck in reverse driving it into the grave, crushing Cuddles.
 * All Flocked Up: Tries to pop his balloons with a rock, but accidentally throws it at Toothy, causing his face to land in hot tar (debatable, may simply be a wrong aim).
 * Something Fishy: Uses the fish bowl as the Helmet.
 * I Nub You: Sews Handy and Petunia together, and ends up sewing his own arms on them.
 * See You Later, Elevator: He uses an elevator during a fire, which isn't safe. Tries CPR on the lower half of Cuddles' corpse.
 * Milk Pong: Chokes on a ball, later drinks bleach instead of milk, doesn't notice a rat in the cup (twice), and tries to get the ball out of a wood chipper with his bare hands.
 * The Chokes on You: Eats donuts while working, and doesn't chew before swallowing.
 * Brake The Cycle: Spills too much gasoline while pouring it into his motorbike, which let him getting burnt to death.
 * All In Vein: Leaves Giggles in the fridge for too long, causing her blood to harden. He later drinks too much blood, causing him to go overweight.
 * No Time Like the Present: Brings Handy a pair of mittens, ironic considering his lack of hands.
 * You're Kraken Me Up: Instead of rescuing Russell, he saves the kraken tentacle with Giggles' head on it, thinking it was Giggles. He makes a similar mistake later on by feeding a bottle of milk to Cub's head attached to a tentacle.
 * All Work and No Play: Attempts to save Nutty by jack-hammering the top of the wall, resulting in his torso getting completely mangled. Later saves Sniffles, but is distracted by Lammy, resulting in him getting smashed to pieces by the excavator's buckets closing in on his head. (Lumpy ironically, knows Lammy is already impaled through the brain earlier in the episode, though it likely distracted him because he thought she was dead and is now walking on her own with an injury that should be impossible to survive).
 * A Vicious Cycle: Eats chips out of Disco Bear's brain. While hiding in from a possessed tricycle, he bites a chip and the crunch noise blows his cover.
 * Spare Tire: Pours too much gasoline into his motorcycle to the point of it leaking.
 * Dream Job: Messes with the television so much that Sniffles' dreams become erased and the TV turns off. Though to be fair, he likely had no idea that's what he was doing and didn't have many ways to. Really it's Sniffles' fault for making it possible for him to do this.


 * Ski Patrol: Messes up and causes the deaths of numerous characters. Though this could also have been the narrator's fault for misinterpreting the instructions, and the fact that the narrator continues to praise him even after such mishaps.
 * Kringle Tree: Smashes Giggles' head trying to chop down a tree with an axe.
 * Kringle Feast: Takes him a long time just to start up a lighter. Then he kills himself (and others) from an explosion because he left the gas open too long while trying to light a lighter. Although to be fair, having a hard time starting a lighter isn't by itself a sign of stupidity.
 * Kringle Frosty: Skis over Sniffles and Toothy, killing them. Although he might have missed them because he plowed through their snowman in the first place.
 * Strain Kringle: Throws a rock at Cuddles and Toothy, when a snowball would have been more preferable (Possibly he was being a jerk).
 * Seize the Day: Uses a defibrillator on Cuddles while he is having a seizure, resulting in his death.
 * Happy New Year: Crashes into Flaky and Russell, crushes Cuddles, and somehow gets the film wrapped around his body.
 * Moppin Up: Forgets to put a Wet Floor sign while mopping, causing Sniffles to break his head. To be fair, since he was currently in the process of mopping so the sign shouldn't have been necessary and considering that Sniffles didn't notice Lumpy mopping, he certainly wouldn't have noticed the sign.

Sniffles
Despite being considered the most intelligent character in the series, Sniffles has caused just about as much ignorant actions as the others, more so usually as a result of pride or arrogance.
 * Spare Me: Attempts to toss a bowling ball using his snout, leading his head to be torn off.
 * Blast from the Past: After dropping a glass of milk, Sniffles decides to build a time machine rather than cleaning the mess and replacing the glass. Doing so leads him to create various time anomalies.
 * Concrete Solution: Carrying Nutty in an ambulance, Sniffles forgets to strap down his patient's gurney. He finally attempts to do so while still driving his vehicle, causing a crash as well as his fate.
 * Wingin' It: Being the only pilot operating a plane, it was rather unwise of him to encounter Lumpy personally. He could has simply spoken to Lumpy via speaker.
 * Tongue in Cheek: Even after being painfully tortured once, Sniffles' determination to eat the Ants consumes him and he tries to use a mind-control helmet and robot to do the job. The Ants once again get the upper hand and kill him in gruesome, agonizing ways.
 * Wrath of Con: He asks Splendid for an autograph while Splendid was busy holding up a chunk of debris. To be fair, this could also count in Splendid's accord.
 * All Work and No Play: Sniffles, along with Lammy and Nutty, decide to play on a playground that is clearly still under construction. In particular, Sniffles goes down a slide despite it having holes in it, causing his body to be grated like cheese.
 * Pet Peeve: Similar to Concrete Solution, Sniffles does something without stopping the car first. In this case, checking on his pet after it makes a hole through the floor. This sends the vehicle into a sidewalk where Sniffles gets his scalp sliced off.
 * Moppin Up: With a big puddle visible on the floor, Sniffles should have watched where he was going.

Nutty
Nutty has done many things that endanger his and others' lives, mostly because of his candy addiction.
 * Class Act: The entire fiasco all started when Nutty bit a chunk off Sniffles' body, dressed in a candy cane costume.
 * Stealing the Spotlight: Seeing a string of Christmas lights as candy, Nutty swallows them and gets disembowelled by Lumpy as a result.
 * Concrete Solution: Hanging onto the edge of a bridge for dear life, Nutty begins eating it after realizing it is made of sugar. It comes to the point where he bites off one last bit of the bridge holding two halves together, leading him to be violently ripped in two.
 * A Sucker for Love: Upon bashing a gumball machine open, Nutty places a handful of gumballs into his mouth, along with shards of glass. He gets his teeth and gums cut, followed by his face when he blows a gum bubble.
 * All Work and No Play: Nutty, along with Lammy and Sniffles, decide to play on a playground that is clearly still under construction. In particular, Nutty rides on a swingset located dangerously close to a bunch of large nails, to which he soon gets impaled.

Pop
Almost earning a reputation similar to that of Lumpy, Pop's stupidity derives from his incompetent parenting, usually the result of Cub's deaths and injuries.
 * Snip Snip Hooray!: He accidentally cuts off one of Cub's ears with scissors. Then he leaves Cub unattended with a razor, paying no attention as Cub puts the item in his mouth as he activates it. He is oblivious to Cub's following death.
 * Water Way to Go: He buries Cub in sand from the neck down and abandons him to get ice cream. Cub gets submerged in high tide and Pop believes his son has been washed out to sea. He brings a boat on the water, running over Cub's head and ultimately shredding him to death with the motor.
 * Read 'em and Weep: Cub is turned back to his normal self after The Demon that possessed him was removed by Lumpy. Unfortunately, out of fear, Pop flattens him using a shovel.
 * Clause For Concern: In a post-credits scene, Pop crushes Cub by closing a door on him.

Cub
Cub's stupidity is excusable, since he is very young and has little understanding with the concept of death.
 * Rink Hijinks: He rips Lumpy's heart out using a claw in a toy machine, then hugs the organ thinking it is a toy.
 * Cubtron Z: After being reincarnated into a giant robot, he uses Cuddles, Giggles and Petunia as crayons to draw on a building.