In Haredevil Hare (1948), Marvin leads the Mars to Moon Expeditionary Force, which consists of Marvin and his dog.

On numerous occasions, Marvin has tried to destroy the Earth with his "Illudium Q-36 Explosive Space Modulator" (sometimes pronounced "Illudium Pu-36"). He always over-pronounces the name of the device, which resembles a stick of dynamite, in order to avoid any possibility of confusing it with some other, more primitive type of explosive technology.

Marvin is often accompanied by his dog K-9, and sometimes by other creatures (one gag, first used in "Hare-Way to the Stars", being candy-sized "Instant Martians" that become full-size on addition of drops of water).

Marvin has been trying to destroy the Earth for more than two millennia because it obstructs his view of Venus.

Marvin is best known for his quotes "Where's the kaboom? There was supposed to be an Earth-shattering kaboom!" and "This makes me very angry, very angry indeed." (which is usually followed by huffing and puffing).

He wears a Roman soldier's uniform, with old-fashioned basketball shoes. The style of these shoes resembles the Chuck Taylor All-Stars brand name, considered to be the "generic" or "standard" basketball sneaker.

Marvin the Martian is named the referee for the iconic match due to the fact that he is both a Toon and an Alien, and therefore the most likely to remain impartial.

His head is a black sphere with only eyes for features.

Marvin has been tasked with locating the uncharted "Planet X", the only remaining source of the dwindling element Illudium Phosdex, a.k.a. "the shaving cream atom".

In nearly all of his appearances, Marvin is shown using a futuristic pistol-like firearm that fires either bubbles of pliable plastic or energy beams. He calls it the A-1 Disintegrating Pistol.