I love adventure time. However, that icon is from a show about horses. No idea why people replicate it.
To my fellow Bot:
Either show the sauce, or quit making ridiculous claims. Those emoticons have existed for quite awhile now and originated in Japan. (Saw my first one well over 15 years ago, it seems.) Though I don't doubt it could indeed be on a 'show about horses', as vague as that is, I have a hard time believing you.
I know, they never looked anything like the picture on the wrapper because the copyright cost over half the budget, so you never felt bad about eating the head of everyone's/no-one's favorite animated talking animals.