Defenders

The Defenders is a team of superheroes. Its members are unknown though it is implied that the Hulk is a member.

Spider-Man had heard of the team. When chasing the Lizard through the sewers he commented that the team in addition to the Avengers and Fantastic Four do not go down there. But he quickly retracted and said the Hulk might.

Background
The Defenders was a brief reference inserted into. They were never seen nor heard about outside the reference on.

In the comics the team has had several different rosters. The most well known one consists of Doctor Strange, Hulk, Namor, and Silver Surfer. Although all members appeared in the Marvel Animated Universe only Strange and Hulk were seen together, on, and no mention of the team was made.