Lee Seitz has an authoritative site on Rom, The Space Knight, a Parker Brothers robot action figure that was pretty cool even though it flopped. I had a couple of these when I was a kid. Looks like go for about $200 if you can find them MIB on EBay.
It wasn’t that cool of a toy.
There was also a tie-in with a Rom comic from Marvel which ran for 75 issues. Hey, maybe someone should ask Michael Brian Bendis if he’s interested in doing an Ultimate Rom!