Basilisk

The basilisk, also known as the curse toad due to its method of attack, is an enemy encountered first in the Depths in Dark Souls. Technically, encountering one is completely optional there.

The basilisk is a slender, scrawny lizard with enormous, bug-like eyes. Upon seeing the player, it will frantically scramble into position and begin firing a grey mist that will quickly overwhelm the player with the Curse status, causing immediate death. The basilisk deals no other effects or any direct damage in any form.

The basilisks in the Depths fittingly guard the Ring of the Evil Eye.

Attacks

 * The basilisk's melee attack is to puff up like a frog and spew a grey mist in a wide radius around its front. This deals no damage, but rapidly applies Curse. It can easily be avoided by moving out of the mist, particularly behind the basilisk.
 * The basilisk's ranged attack is to leap into the air and fire a grey ball projectile at a spot on the ground, usually just at the player's feet. This will cause the cursing grey mist to spread at that location.

Melee
Basilisks cannot attack behind them in any form, and their melee attack is incredibly slow; as long as they're not encountered in large groups there should be no problems flanking and dispatching of them.

Ranged
Basilisks stagger from just about any hit, and can easily be pelted with arrows without their being able to execute a single attack. This gives the added bonus of allowing players to pull one or two basilisks at a time, rather than have the entire swarm of seven or so rushing after them; players are also advised to be carrying arrows anyway as slimes are not far away from basilisks.