Zoro

The Zoro is a rare enemy that appears in later dungeons of A Link to the Past. Occassionally when Link opens a doorway in a wall using a Bomb, these tiny creatures skitter out in small groups. They travel straight downward from the newly opened doorway before disappearing when they hit a wall or obstacle. They are relatively weak and can be easily destroyed by Link's Master Sword, and they won't cause too much damage to Link, but they will continue to appear even when a group is destroyed. Link must be careful when passing through the doorway not to get caught by a newly emerging swarm. The creatures themselves are black and formless, leaving small trails behind them. They are extremely similar to both Boes and Babasu.

Trivia

 * The name Zoro is a play on the Japanese onomatopoeia "zorozoro", which means "to come in droves", describing the behavior of these creatures. Another enemy, the Beetle is actually called Zoro Zoro in Japan.