Ceratogyrus brachycephalus (Greater horned baboon tarantula) is an old world terrestrial tarantula

Tarantula

Tarantulas comprise a group of often hairy and often very large arachnids belonging to the family Theraphosidae, of which approximately 900 species have been identified. Some members of the same Suborder may also be called "tarantulas" in the common parlance. This article will restrict itself to...

 that grows to a legspan of up to 5 inches (12 cm). The common name comes from the "horn", or protuberance, on the carapace.

Pet tarantula

Ceratogyrus brachycephalus is a relatively common tarantula for hobbyists to keep. It prefers to burrow, but in the absence of substrate to burrow it will web and make web "tunnels". This species is extremely fast and aggressive; care must be taken when performing tank upkeep. Some people surmise that what is commonly called C. brachycephalus in the pet trade might actually be Ceratogyrus sanderi, or maybe a hybrid.