I'd be up for it if I wouldn't be the only one playing a Transformer and contributing to that particular corner of the Independent Game's universe. If I took up Galvatron for instance, it'd be pretty un-Transformers-y unless there were Autobots to play off of and do intergalactic war stuff with. If it were just Galvatron vs. the Ninja Turtles, Hellboy, or even G.I. Joe, it still wouldn't really feel like I was RPing as a Transformer.
I kinda ran into a similar problem way back after I applied for Big Head (the Mask), and then realized that there were no real conflicts that the character would care enough about to get into (plus he was too overpowered to get involved in other players' stories without derailing them instantly) Sure, like Galvatron, I could come up with a single player story and NPC some opponents and conflicts for Big Head, but I'd be writing full-out fanfiction at that point when what I signed up for was role playing.
Still, if there were Autobot players in the game, I'd definitely give it a shot. But then I look at our currently short supply of active RPers around here, as well as the people on that list who'd also be willing to play an Autobot, and my hopes kinda go down.