Looking back now, the go-bots really did suck

[ShadowBoxing]

Prime-based animal transformers appeared as various animals in various series, including a bat (early Beast Wars toy line), gorilla (Beast Wars) and lion (Beast Wars Neo, a Japanese series). Out of those three, I'd say a gorilla certainly makes the most sense.

Don't forget a Mastodon (Beast Wars II - "Big Convoy"), although neither nor Lioconvoy were ever referred to as a 'Prime'. Such a distinction doesn't exist in Japanese fiction.

Also, the Bat toy Optimus Prime is actually the real Optimus Prime, unlike Optimus Primal who is a descendent. Though the cartoon panned out different, initially planning indicated that it was supposed to take place directly after the events of "Return of Optimus Prime" (and I suppose "Rebirth"). That the characters in question were supposed to be organic modifications of G1 era Transformers.