Even if it's "Northrop-Grumman," Grumman as a builder of aircraft is no more. Northrop really just bought the name. Sort of like Callahan Brake Pads.
I dig what you're saying about cat names for Grumman planes only, though.
If Clinton was still in office, I'd say Razorback would be a contender. As it is, since there's already a "Texan" flying... Avenger is out, even though that's what Bush I flew in the Big War, since it was the name of the ill-fated A-12. Ranger, maybe?