Detective Chimp is a talking chimpanzee, who is the host of the powerful demon Etrigan.
Featured in these Comics
Other Personas of Bobo T. Chimpanzee
History
After Merlin began his war against magic by splitting the demon Etrigan from his human host Jason Blood, Detective Chimp became the demon's new mortal bond. He worked with Zatanna to try and stop the wizard, although they were constantly falling behind him. With the aid of Etrigan, Ragman, and most importantly Doctor Fate, the Justice League Dark managed to drive Merlin back, albeit temporarily.
While Bobo's ultimate fate is unknown, in the 853rd Century Etrigan wore an outfit reminiscent of the chimp, suggesting that their bond continued long enough to have a big impact on the demon, if not all the way until that far future era.