Artwork by vrt, so props to him
This is the first in a set of 'Trickster' cards designed to mess with the mind. The element is Entropy since it's chaos based and what else is better suited for deception?
Mechanically a bit tricky (what else would it be?) but could be done by tweaking some of the existing mechanics. In essence, it comes into play like a normal creature, but it's appearance is decided upon playing the card. Fate Egg comes into mind for a similar mechanic, although this will just decide the card's appearance, but not it's mechanics. The tricky part will an optional part: Fooling the AI into thinking it's what it seems.
When about to be killed, it will 'escape', which acts like an emergency Rewind on itself. (may cost quanta to perform, if deemed necessary) This does not trigger any death based bonuses to skills such as Devour, Bone Wall, or Scavenger.
The Trickster's function is to get your opponent to waste cards trying to get rid of him, thinking he's a threat. The pool of creatures it can appear as could be modified to be all the 'dangerous' ones in order to facilitate this. And since it escapes, one can never be sure it won't show up again... of course, you could carefully watch the quanta spent when it's played, but can you be vigilant against deception every turn?
When upgraded, mana cost drops to 3 and and all 'disguises', so to speak, are elite creatures instead of normal ones.