Mongbats

A cross between a monkey and a bat. Mongbats are strong and vicious, attacking their victims with strength and without fear. A large number of these winged anomalies, which had developed in the Underworld, can threaten an experienced group of adventurers.

Mongbats usually dwell only in dungeons, but they are also seen in the wilderness on occasion.

First seen in Ultima V, they stayed the same in all their appearances, although in both Underworlds, Mongbats were stronger to give the player more of a challenge.

Trivia

 * Mongbats were to be included in the cancelled Ultima X. Link: Ultima X Mongbat