Martin Tentacles is the main protagonist of the MTV's animated television series, Planet Tentacles.
He is the 30-year old son of Sir Tentacles and Chloe Tentacles, Ann Tentacles's girlfriend and later fiancé, father of Pearl Tentacles, Ren Tentacles, Clarence Tentacles and Bob Tentacles, and the (former) friend-in-law of Little Brother.
He is voiced by Jonah Hill.
Martin P. Tentacles was born to Sir Tentacles and Chloe Tentacles in the place away from Planet Earth in the space named Planet Tentacles.
During Martin's childhood, he loves eating pizzas and playing video games and he also hates spinach, as revealed in the "Origins".
In 2000, he became part of the Pizza Cabin along with Jim and later, after Jim had quit, with a fry cook whose name is yet to be revealed. One day, Martin was swimming with his dolphins when suddenly, two fishermen from a boat captures him and mistakes him for eating him as the fishermen's food. One night, he escapes from the boat and meets Ann Tentacles.
He is heroic, funny, kind, nice, brave, still funny and cowardly. Sometimes, he is grumpy and antagonistic towards Roward.
- Although one of the two protagonsts of the series, he is also the antagonist, towards Ann, Roward, Little Brother, Brain Gremlin, Stripe and the Gremlins.