Alvin Seville

Alvin Seville is the leader of The Chipmunks and is the self-proclaimed "awesomest" one. As the leader, Alvin is usually able to convince Simon and Theodore to go along with his "half-baked" schemes. Alvin has been shown at times to be quite self-absorbed and greedy, but at others to be selfless, and giving. Alvin is also an emotional rollercoaster, his enthusiasm endless, and despair bottomless. The term "look before you leap" does not apply to Alvin, who is spontaneous and impulsive.

Alvin is the oldest of the 3 Chipmunks as revealed to us on the episode "Grounded Chipmunk".

Alvin has a love/hate relationship with Brittany of the Chipettes.

Biography
Alvin life is like a roller coaster. His enthusiasm is boundless and his despair bottomless. The term look before you leap definitely doesn't apply to Alvin, who is impulsive, charming, musical and full of animal magnetism. The character, who is heavily based on former member James Sawyer always seems to make up hare-brained schemes to get what his goal at the time is, whether it be trying to help his brothers, or keeping Dave from figuring something out, or getting out of a sticky situation. However, Alvin seems to refer to his often illogical or crazy plans as "challenging the ordinary".