The Acromantula are a species of giant spider, native to the rainforests of Southeast Asia, particularly Borneo. Acromantulas are believed to be a wizard-bred species, designed to guard dwellings or treasure hoardes, and were first created before the Ban on Experimental Breeding in 1965. They have a taste for human flesh.

Acromantulas have eight eyes, are highly intelligent and capable of human speech. They are typically covered in thick black hair, with a legspan that can reach up to fifteen feet. They possess a set of giant fangs which they use to eat live prey of mammals or their own dead kin. The pincers produce a clicking sound when the beast is agitated or excited. These fangs contain highly toxic venom, valued at 100 Galleons a pint, which is even potent for a short time after death.The eggs are Class A Non-Tradeable Material.

The female is usually larger than the male, and can lay up to one hundred soft, wide, beach ball-sized eggs at a time. They usually hatch in six to eight weeks.

Acromantulas tend to reside in jungles and heavily forested areas, and their webs are large and dome-shaped.