Marvin hails from the planet Mars, but is often found elsewhere. He is often accompanied by his dog, "K-9," and sometimes by other creatures. Marvin wears a Roman soldier's uniform (a reference to Mars being the Roman god of war) with old-fashioned basketball shoes. His head is a black sphere with only eyes for features. The crest of his helmet appears, with the "push broom" like upper section, to "comically" resemble an ancient Greek Hoplite's helmet. The appearance of the combination of Marvin's head and helmet allegedly led to Bugs Bunny thinking he was a "bowling ball wearing a spittoon" in one Looney Tunes animated short. Marvin is given a timid, nasal voice. The helmet and circle that surround him are green and he wears a red shirt and red pants. He is also known for his trademark quote "Where is the kaboom, there was supposed to be an earth-shattering kaboom!"