JBCrowson
Inkling
The original dungeon keeper game (showing my age here - it was released in 1995) allowed the player to 'possess' their minions and thus see the game world differently. One minion was a 3 headed hell hound - possessing it gave you a monochrome view port; the fly gave you a confusing compound view of the game world.Changing shape would be hard on the body. Expect joint problems as the shifter ages. Also, humans have better vision than most other animals, so there is a good chance the shifter would be colorblind - maybe monochrome, maybe green/red colorblind. Those bring up some interesting possibilities.