The characters on Adventure Time are purposely drawn in a completely unrealistic style to suit the strange and silly tone of the show- and because they would look totally creepy if drawn to look realistic.
In fact, most of the characters on the show would probably look quite horrifying in real life and give kids nightmares, especially Simon the Ice King and that sourpuss the Earl of Lemongrab.
Sculptor Adam Edwards decided to show the world just how creepy Lemongrab and the Ice King would look in real life by creating unnervingly realistic busts of the two baddies.
This transformation has not only caused the characters to lose their cartoony appeal- it has taken them from the Land of Ooo and transported them straight to Westeros!
-Via Laughing Squid