The Ultramorph is a Xenomorph born from an Engineer. The Ultramorph is depicted as being huge in size, far larger than any typical human-spawned Xenomorph. Its height is most likely 16+ feet tall. Most uniquely, the Ultramorph posesses large, almond-shaped eyes, a feature rarely seen in most Xenomorph breeds.
The Ultramorph was featured in Jon Spaihts' original Prometheus script, but was ultimately cut from Prometheus before filming, replaced instead with the Deacon, a creature born from a Trilobite impregnating an Engineer.
- In Alien, Dallas, Lambert, and Kane encountered a derelict space ship on LV-426 and found inside a deceased Engineer pilot with a large hole torn in its chest, its ribcage bent outwards, the result of a Chestburster emerging from within. The resultant Xenomorph, however, is never seen in the film, and owing to the fossilised nature of the Engineer's corpse it seems likely that it has since died of either starvation or natural causes.
- The Aliens comic, Destroying Angels featured a similar creature called the Destroyer.
- In the Nintendo DS game, Aliens: Infestation, a Jockey spawned Xenomorph appears as the second boss of the game. Its appearance is considerably different from that seen in Destroying Angels and the Prometheus concept art, as it possesses a trunk and clearly visible eyes. It attacks by stomping, swiping and regurgitating large quantities of acid.