Karmak

Karmak also known as Professor Gorilla or the Beast-Bomb is an animal adversary of Batman.

Pre-Crisis
Karmak was a lab-rat gorilla experimented on a scientist named Walter Hewitt with Hewitt trying to give himself gorilla powers. The experiments gave Karmak hyper-intelligence and the ability to mind-control, which he used to mind-control the scientist into commiting crimes.

When Batman intervened, Karmak began draining the dark knight of his intelligence and fighting abilities to use for himself. When Karmak realized that his powers of intelligence-draining was only temporary, he created a super-bomb which he used to try and suicide-bomb all of Gotham. He was defeated and put into captivity where his intelligence completely faded, after which he was returned to the jungle.

Karmak's story was retold in Jiro Kuwata's 1966-1967 Bat-Manga!: The secret history of Batman in Japan where he was reintroduced as Prof. Gorilla and given a much more ominous costume with a dark mask, glowing eyes and a cape.

Post-Crisis
Karmak briefly appears in the Batman Incorporated storyline, Mr. Unknown is Dead. In this, Prof. Gorilla is a super-villain in Japan who becomes an adversary of the Japanese Batman, Jiro Osamu after his predecessor Mr. Unknown is murdered by Lord Death Man.

Prof. Gorilla's appearance in Japan being a clear homage to Bat-Manga.

New 52 (Prime Earth)
In the New 52, Karmak is a spy for the US government agency of ARGUS. He is sent to the African city-state of Gorilla City to act as a spy due to the entire city being populated by intelligent gorillas. He is sent there to spy on the known telepathic super-villain Gorilla Grodd who had taken over the city but he is found out and tortured by Grodd. Eventually he is rescued by Wonder Woman.