Pet Ultralisk.
We ended up removing the lower arms for a cleaner in-game read.
FX models
This idea had been suggested in many forms for quite a while, and it was a heap of fun to get to go all out on it finally.
Base Kerrigan model by Phill Gonzales, Ted Park and Vadim Bakhlychev; base Ultralisk model by Jarred Everson and myself.