If Cerebros and Craniak had alt-modes besides heads, what would they be? I could see Craniak turning into either a nepidae or a jet, and I could see Cerebros turning into either an SUV or a space shuttle.
Dear Cerebral Contemplator,
In one universe, Craniak was the leader of the team of Decepticons who pursued the Autobots to Nebulos. In this reality, it was the Decepticons who pioneered the Headmaster process; Craniak forcibly recruited Lord Zarak to bond with him, intending to use his unwitting partner's knowledge of Nebulos to turn the organic world into his own personal science facility. He might have succeeded, had Autobot lieutenant and would-be pacifist Cerebros not undergone the binary-bonding process himself, merging with Nebulan anti-government agitator Spike.
...Ah, but I'm getting away from your actual question. This version of Cerebros transformed into an armored personnel carrier, similar to the Cerebros seen in IDW Publishing's The Transformers: More than Meets the Eye. Craniak, meanwhile, transformed into a huge mechanical cephalopod. Now that I think about it, he bore more than a passing resemblance to the Tako Tank piloted by Ikard during the Beast Wars on planet Gaia.