I do enjoy humor in games, but Monty Python style silliness on a character-defining standard-action is too much.
In an adventure game disguising as a rock or snowman and then tiptoeing past a guard would be a funny way to solve a puzzle and at the same time highlight the flaws of the common crpg stealth mechanics. Doing it a second and third time, or even more often maybe with some tounge-in-cheek comment about the actual silliness, is something I totally expect from
Hero-U: Rogue to Redemption but not from an rpg where 1/3 of the character builds will constantly turn into a rock/bush/snowman intending to do some very serious business.