Predacon. It's really a very simple transform -- his legs and arms tuck in a bit, and he's done.
What's fun about Divebomb, for me, is the serendipity surrounding his name. You see, Divebomb was a name proposed by Bob Budiansky for Swoop. For whatever reason it was rejected, but Furman picked up on that and had Swoop make reference to 'back when I was Divebomb' in a story. Lo and behold, a Decepticon named Divebomb shows up the next year, and so Furman weaves this together into a story about how Swoop lost his name to this Predacon. Nifty stuff; Furman seems to excel at taking lemons and making lemonade.