Arachnotron

The arachnotron (sometimes called Baby spider) is a monster introduced in Doom II. It is a smaller cousin of the Spider Mastermind that fires green plasma shots rather than bullets. Once the Arachnotron engages an enemy it will continue to fire until the enemy moves out of its field of view or until the Arachnotron flinches in pain. Similar behavior can be observed with the Chaingunner and Spider Mastermind.

Although they may seem slow, Arachnotrons are acutally faster than pinky demons and can catch up with the player at a frightening pace. They have a medium pain chance, so rapid fire weapons will work well but chainsaws are very risky. Their attacks are easier to avoid than those of chaingunners and spider masterminds, but the plasma bolts move faster than most other projectiles and can do very quick damage to the player if not avoided. If the player constantly attacks, moves in broad side-to-side movements, and tries to get out of the Arachnotron's line of fire periodically, then the player will sustain minimal damage.

According to the manual:
 * Maybe cybernetics wasn't such a great idea after all. Look what the demons have done with it. It seems unfair somehow you're not the only guy in Hell with a plasma gun.

Arachnotrons are not specifically present in the Doom novels, though Marines on Earth mention having encountered them in battles.

Appearance statistics
The IWADs contain the following numbers of Arachnotrons: