Happy Tree Friends Wiki
Happy Tree Friends Wiki

A mental disorder or psychiatric disorder is a Mind mental or behavioral pattern or anomaly that causes Suffering distress or disability, and which is not developmentally or socially normative. Mental disorders are generally defined by a combination of how a person feelsacts, thinks, or perceives. This may be associated with particular regions or functions of the brain or rest of the nervous system, often in a social context. The recognition and understanding of mental health conditions have changed over time and across cultures and there are still variations in definition, assessment, and classification, although standard guideline criteria are widely used. In many cases, there appears to be a continuum between mental health and mental illness, making diagnosis complex.

Known characters with mental disorders


An example of Flippy's Post-Traumatic Stress disorder.

Main article: Fliqpy

Flippy has severe Post-Traumatic Stress Disorder (PTSD), which causes him to "flip" out and think he's back in the war whenever he's reminded of the war. When reminded, his pupils dilate, his irises becomes yellow-green, his voice goes from squeaky to a deeper, darker voice, and he becomes extremely violent, losing any shred of empathy he had and committing murder. Given the nature of this reminder, it's also possible that he has Dissociative Identity Disorder also known as Multiple Personality Disorder.

Lammy and Mr. Pickels (Debatable)

Lammy has schizophrenia since she always sees Mr. Pickels as a living creature while everyone else just sees him as an ordinary pickle. Therefore, Lammy is killing everyone herself, but since she denies the fact that she would ever harm someone, she uses her wild imagination to conjure up Mr. Pickels as the scapegoat for her crimes. However, it may just be possible that Mr. Pickels actually is alive and is the true murderer (as seen in Royal Flush). If not schizophrenic, Lammy may have some psychopathic tendencies considering that she clearly knows that Mr. Pickels is a serial killer but insists on carrying him around everywhere she goes.

Despite debatably being the result of a mental disorder himself, Mr. Pickels appears to be a psychopath, as he seems to kill Lammy's friends for fun, and also took pleasure in killing inanimate objects, such as a sockpuppet and a teddy bear. It is also theorized that he may kill other characters around Lammy out of fear that they may replace him as her best friend, so therefore disposes of them to ensure that.


Petunia's Obsessive Compulsive Disorder.

Petunia has Obsessive compulsive disorder (OCD), specifically, mysophobia (fear of germs and disgusting things), causing her to excessively clean and wash things, even if it isn't her stuff. In Wishy Washy she clearly exhibits the severity of her disorder by constantly hyperventilating whenever anything was out of place, and more famously, her death in the episode: having being driven insane by the dirt covering her body and not being able to wash it off due to the broken plumbing system caused by Lumpy, Petunia proceeds to "clean" herself by cutting, shaving and slicing off her own fur and skin with a potato peeler, killing herself in the end and leaving her corpse to fall to the ground with a deranged smile.

  • Her OCD was brought up in other episodes:
    • Home Is Where the Hurt Is: Petunia was tasked into putting pipes together and a splotch of slime lands on her chest and starts hyperventilating because of it. In a panic, she puts Lumpy in charge of putting the pipes together instead while she takes care of the blemish by using a cooler to clean herself. She hyperventilates again when she noticed slime was falling from a grate in the ceiling, and she forces herself to clean it. Later in the episode, she got covered in blood and guts after Lumpy got smashed by a fold-in bed on the second floor and his remains fell through the grate. Petunia began screaming because she was messy, so she instantly jumped in the shower while whimpering in fear. Suddenly, she gets electrocuted, because earlier, Petunia told Lumpy to put the water pipes together while she desperately tried to remove some bacteria from a pipe that jumped on her body. Lumpy unknowingly mixed water pipes with electrical pipes, causing Petunia to get electrocuted when she took a shower.
    • Wingin' It: When Flaky got queasy after Mime was explaining how the plane could crash, she tried to get a barf bag, but Cuddles was using them as puppets, so she ran into the bathroom. Moments later, Lumpy was using his cellphone, which caused the plane to shake violently. Flaky begins getting tossed around the bathroom, spreading her vomit all over the walls. Petunia, desperately needing to use the restroom after drinking one too many drinks, runs in when Flaky exits. Petunia sees the vomit and she's shocked. She tries to escape the bathroom, but Mime put a food rack in front of the door, causing the door to get blocked. Later, Petunia cleans up all of Flaky's vomit. But when she washes her hands, the air suction of the drain pulls her deodorizer, causing her body to get sucked down, and her organs to get squeezed out of her body.
    • Something Fishy: She had very little reaction beyond curiosity when she heard Giggles' screams but as soon as the blood started leaking into her stall, she immediately panics pulling her feet out of reach of the blood puddle and tried to get the heck out of there but had no toilet paper. (Debatable)
    • Royal Flush: This is the first time we see her OCD in an obvious way outside the TV series. She was seen vacuuming a few bread crumbs off a table with a hand vacuum at Lammy's house; this reveals that she tends to clean up no matter whose house she's in. Later, Petunia screamed in horror because there was an olive with a toothpick on the floor, and she began hyperventilating quietly. She instantly grabbed a vacuum, and sucked up the small topping, then she sucked up Mr. Pickels, who was on the floor intentionally. Petunia put the nozzle next to her eye, which began to suck out her organs. Then when Lammy put the vacuum from suck to blow, Petunia bloated up like a balloon until she popped.

However, even staying in the TV series, her OCD isn't always in existence, most notably, in Take a Hike, she drank very filthy, clearly contaminated water with no reservations, though she mainly did this because she was very thirsty and desperate.


Russell suffers from some kind of insanity disorder (possibly hysteria). This was revealed in Get Whale Soon. After being swallowed by a whale and accidentally killing Lumpy, Russell was driven mad; his eye turned grey, his mouth became crooked, and he started slashing things with his hook while laughing maniacally. This is further implied in Something Fishy, where he is shown to have a crack on his skull, similar to Lammy. Though to a much lesser extent, we see a bit of his insane state in Snow Place to Go while he's trying to escape the orca.


Ornithophobia: the fear of birds.
Alektorophobia: the fear of chickens.

Flaky has a long list of phobias due to her constant anxiety and cowardice (and could be a phanophobe). She suffers from alektorophobia or ornithophobia (Chickens or birds; From A to Zoo), achluophobia/nyctophobia (darkness; Without a Hitch), necrophobia (dead things; Snow Place to Go), amaxophobia (driving; Easy Comb, Easy Go), aerophobia (flying; Wingin' It), acrophobia (heights and skiing; Mime to Five and Ski Ya, Wouldn't Wanna Be Ya!), musophobia (rats; Out of Sight, Out of Mime), coasterphobia (roller coasters; The Wrong Side of the Tracks), hydrophobia/aquaphobia (water; Wipe Out!), and Selachophobia (sharks; Wipe Out!). All these phobias reveal that Flaky is almost scared of everything. Strangely, in Take a Hike, she wasn't scared of a bird that fell out of its nest, but in From A to Zoo, she WAS scared of birds, as she bellowed in terror when one little chick was trying to hop over to her, though this could just be she is only afraid of chickens, not all birds. Flaky is also shown to go insane when trapped in unknown locations, as seen in Snow Place to Go where she is the only character to go insane from being left in the arctic long and in Without a Hitch, her fear made her commit a homicidal act towards Flippy, where she stabs him in the eye.


Desperation at its finest. 10 out of 10.

Nutty is shown to have a serious addiction to confectionery and other sugary foods. His care for candy often overshadows his care for his friends. This was evidenced in A Sucker for Love Part 1, where he stole Cub's giant lollipop and showed no sympathy for Cub, even when he was crying over his lost sweet. Also in A Sucker for Love Part 2, while he never actually does anything, he imagines himself killing Lumpy over a box of chocolates. This was also evidenced in Party Animal: When Flaky was experiencing an allergic reaction to peanuts, Nutty gets worried and proceeds to help. Unfortunately, he instantly becomes distracted by a platter of chocolate chips on the counter. Taking a while to decide what to do, Nutty ultimately pushes Flaky aside and chooses the chocolate over his poor friend. It is also revealed in Nuttin' Wrong with Candy that when he fails to get the candy he wants, his mouth starts to foam, which reveals that he has rabies. It is also shown in Party Animal that even the tiniest grain of sugar can make Nutty have a sugar rush and spin around rapidly like a tornado (similar to the Taz from "Looney Tunes"). Nutty is also shown that he can't think straight and he lacks common sense (possibly mentally challenged). This was shown in Chew Said a Mouthful; he broke his jaw after biting a jawbreaker, yet his still wanted to eat it, but it is either indestructible to eat it, or stone-harded, despite the condition of his mouth. His deaths are usually a comeuppance to his irrational behavior towards sweets. 

It might be possible that he also has Attention Deficit Hyperactivity Disorder (ADHD), a disorder that prevents him from paying attention or staying/standing still and imagines lots of candy in floor but that is colored objects. This latter illness has been touched upon most prominently in A Sight for Sore Eyes, where it seemed to have psychically affected his vision as well.

Lifty and Shifty

Lifty and Shifty stealing a cow.

Lifty and Shifty have kleptomania, the inability to refrain from the urge to steal items and is done for reasons other than personal use or financial gain. Because Lifty and Shifty have this disorder, they are always trying to steal at any moment possible. They steal whenever they can, and are seen stealing in almost every episode they're in.

It was debated whether or not Lifty and Shifty actually steal out of need judging by their poor living conditions seen in episodes like Meat Me for Lunch and Buns of Steal. However, in 2015, it was confirmed by Kenn Navarro that they are indeed kleptomaniacs.

The Ants

This infant looks happy for the killing.

At least towards Sniffles, all four members of the Ant Family appear to be sadistic, meaning that most of their pleasure comes from others' pain and/or suffering. This is shown not only through how they brutally torture Sniffles in every episode they appear but they are always shown to enjoy doing so through smiles and even cheers.


It is possible that Handy is a sociopath, as he rarely shows any grief or sympathy when other characters (apart from Petunia and The Mole) die or get injured. At times, most notably in The Wrong Side of the Tracks and Something Fishy, he even laughs or celebrates these casualties. As shown in In a Jam, he also suffers from epileptic seizures.

Disco Bear

Disco Bear checking himself out in the mirror.

Disco Bear appears to be a narcissist which means that he has an obsessive love for himself and inability to see his own flaws. He is constantly seen checking out and praising himself and also seems completely unaware of Giggles and Petunia's hatred of him which is another sign of the disorder. However, in Ipso Fatso, he clearly (and finally) noticed that he has a problem with his weight which is unusual for the disorder.

Mime (Debatable)

Mime may possibly have schizophrenia as he often owns invisible furniture. In Easy For You to Sleigh, he was shocked to see his invisible safe “stolen”. Minor hints of Mime actually having schizophrenia are: him not noticing that his case has been shattered and not escaping Giant Lumpy when he clearly has the chance to in Dunce Upon a Time, and pulling out a dead imaginary Sniffles as opposed to the real one when he was drowning in Mime to Five.