The greater bullsquid (sepiotherium horribilis) is a species of bullsquid in the sepiotherium genus.

Greater bullsquids are aggressive carnivores capable of reaching sizes over 3 meters long. Like all bullsquids, they have a bipedal stance, which sets all sepiotherids apart from their tripedal relatives. their tail is a modified rear leg that provides balance. their mouth is adorned with 6 tentacle-like limbs that conceal the animals sharp serrated beak. they aid in grabbing prey and even provide bullsquids with the ability to hold and modify objects. the inside of the tentacle is lined with fleshy spines similar to those found in bird mouths.

the genus sepiotherium comes from greek σηπία [sēpía] meaning cuttlefish, greek θηρίο [thirío] meaning beast. its species name horribilis is latin and means horrible.