The McDonnell XF-85 [Goblin] was an attempt to provide escort cover for the new long-range Convair B-36 "Peacemaker", in 1947 the USAAF issued a request to the McDonnell Aircraft Corporation to provide prototypes for a "parasite" fighter.
This aircraft would contained within a B-36 "mothership" and be launched and retrieved as needed to counter the threat of enemy aircraft.
Only two "Goblin" were ever built