Dr. Happy is a biologist and owner of an animal sanctuary. His only wish in life is to help poor unfortunate animals. He has a pet dog, Happy Dog who serves as his sidekick.
Timon and Pumbaa come into contact with him in the episode Let's Serengeti Out Of Here. He believes that the pals are endangered (just because he hasn't heard of them) and traps them into the sanctuary. Timon and Pumbaa soon realise that living in a fenced up environment is not for them and plan many (failed) attempts to escape, until they eventually succeed.
Dr. Happy appears briefly at the start of another episode called Shake Your Dijibot, where a potentially dangerous animal breaks free from his sanctuary.
Dr. Happy is voiced by Steve Mackall.