Phanto

Phantos are large, seemingly living or possessed masks that can often be found guarding various treasures, most often, keys.

Phantos appeared as semi-common enemies in Super Mario Bros. 2, often in caves or in vases. Phanto simply remain immobile unless the key they are guarding moves; once this happens, a Phanto will ceaselessly chase whoever stole its key. Phantos cannot be avoided and can only be escaped from using the key it was guarding to unlock a door. If the player simply drops the Key while a Phanto is chasing them, the creature will fly away and leave them alone, at least until the key is picked up again.

Appearances in Other Media
Two Phantos made appearances on The Super Mario Bros. Super Show!. The first one appeared in the episode "The Ten Koopmandments". This Phanto lived in a pyramid that Koop Tut had trapped Mario, Luigi, Princess Peach and Toad in. Upon discovering the four heroes, it proceeded to chase them until they managed to escape from the pyramid, and was never seen again.

Another Phanto made a brief cameo appearance in the episode "Escape from Koopatraz", as a member of Judge Koopa's jury.

Trivia
The name Phanto simply seems to be a shortened form of the word phantom, which is a type of ghost or specter. Phantos were originally half white and half red in color, though there most recent appearances, in Super Mario All-Stars and Super Mario Advance, show them as being brown. The name Phanto appears later in Super Paper Mario. In Chapter 6-3, the Sammer Guy guardian of the 63rd gate is "Phanto Grin".