Anthell (極秘実験生物 アントヘル Gokuhi Jikken Seibutsu Antoheru?, lit. "Top Secret Experimental Organism Anthell") is a boss in Contra III: The Alien Wars. It is an aliens' lair inhabited by giant centipede-like creatures.
An amalgamation of a hard shell encasing what appears to be a large mound of living brain tissue bearing a single eye on its top which acts as its weak spot.
Anthell remains at the center of a giant sand trap and its structure serves as a den inhabited by giant centipede-like alien creatures which can be seen constantly slithering in and out from its four cavities.
At the beginning of the battle, the sand trap is immobile and the centipedes will only come out a certain distance in an attempt to reach the player. Once the eye has sustained enough damage, the sand will start moving and drag and spin the player around, forcing them to correct their aim constantly. In higher difficulty settings, the sand will drag the player further and faster.
The centipedes will now come completely out of the structure and slither after the player. In addition, the cavities will periodically unleash streams of fire straight ahead.
Anthell is one of the bosses that has gone through the most changes in the Game Boy port; instead of releasing centipede-like creatures, it spawns four orbs with spikes from each of its corners; these initially spin around the boss and then are launched at the player.
Instead of having just one eye on its center, Anthell has four this time around, one on each side, and all of them must be destroyed in order to defeat the boss.
The behavior of the sand is also less disorienting than on the Super NES version, merely pushing the player to a side instead of spinning them around.