Muscle

 Muscle is a minor villain in Teen Titans Go! who made his debut in Birds.

Bio
When Muscle first appeared, he was nothing more than a regular mocking bird. He, along with his friend Flex, built a nest inside Titans Tower's chimney. Robin ordered them to leave, but the birds refused, and mocked him. Robin angrily used birdy-cide to poison the mockingbirds, which caused them to leave.

After they had escaped, they both mutated into giant mockingbirds. They instantly gained the friendship of all of the Titans (except Robin). They moved into the tower, and for a while they got along. They threatened to hurt Robin numerous times, until he finally moved out of the tower. Once he moved out, the birds became very obnoxious, and annoyed the other Titans. The other Titans found Robin, and they attacked the mockingbirds, ordering them to leave.

The birds fought back and defeated the Titans, until they used Birdy-cide again. They both mutated into superior beings, and told the Titans they no longer wish to fight them. Robin attacked them and kicked them out of the tower, and they flew away, probably forever.

Abilites

 * Superior Intellect: After evolving, he gained superior intelligence.
 * Near-invulnerability: He is nearly invulnerable, and can withstand everything but Birdi-cide.
 * Super strength: Has the strength to take on all of the Titans, including the super strong Cyborg and Starfire.
 * Laser Vision: He can shoot lasers out of his eyes.
 * Sonic Screech: He has been seen to be able to screech loud enough to knock his enemies into submission.

Episode Appearances

 * Birds (debut)

Trivia

 * He was voiced by Scott Menville, the voice of Robin.
 * The Wilhelm Scream was heard when he and Flex were mutating.
 * His purple mohawk and shades are the same as those worn by the Teenage Mutant Ninja Turtle villian, Bebop.