User blog comment:IThrowLemonsAtLife/Heartwarming/@comment-26365046-20160222015321

Petunia having Disco Bear taken to the hospital in A Change of Heart despite how much she dislikes him and I like how concerned she is over seeing him lying on the ground.

Sniffles fixing Nutty instead of letting him go after healing him in False Alarm.

Lumpy picking up Whistle when the sun went down with a caring face despite everything the thing put him through.

Lumpy being constantly inspired by his hero in Letter Late Than Never.

Pop crying and hugging Cub in And the Kitchen Sink after they both fell of the waterfall.

Lumpy and Toothy laughing together in Idol Curiosity.

I'm sure there more but these are the ones I can think of by mind.