Protean

Proteans are serpentine outsiders of pure chaos native to the Maelstrom.
Traits: Blindsense (distance and sense varies by protean type immunity to acid; resistance 5 to electricity and sonic (CR 3+; increases to 10 at CR 7, 20 at CR 11, 30 at CR 15 supernatural flight speed; amorphous; change shape; grab ability with its natural attacks.