Kp live rock hitchhiker

[WyoMt.Chef]

Hello all! Currently curing 10lbs kp aquatics and I have a odd little gel bump that's seeming to grow appendages or nodes?!? They seem to be stationary as far as placement but are extending upward. Someone has suggested chitons or a sponge but am having a hard time finding anything in those categories that resemble it. The first two photos are when I received the rock the and the second two a day later after I noticed the changes. Any help appreciated!

 

[dimitrinivo]

possibly a tunicate? basically a sponge with nerves