The Beast Within

From Hulk Wiki

David takes a job at a zoo in order to learn more about the research of a controversial scientist studying animal aggression. When David discovers that the insecure young woman is being framed by several corrupt zoo officials involved in diamond smuggling operation, it will take the power of the creature within him to resolve the situation. Comments: A very charming episode marred only by an incredibly stupid confrontation between the Hulk and a cheesy looking gorilla (aka man in a gorilla suit). The scripting is superb, expertly showing the compassionate side of David Banner. If only they had decided to leave "Elliot" in the background.