Mongbats

Mongbats are a type of monster native to numerous worlds which resemble a hybrid between a monkey and a bat. They appear in Ultima V,  VI,  VII and   VII Part Two, as well as the Ultima Underworld series.

Description
Frequently attacking in small flocks, mongbats congregate in dungeons and in mountainous areas. They assail their victims bare-handed, not appearing to have any proficiency with tool use, and tend to follow an attack pattern in which they swoop down to attack a victim before circling out of reach. While a single mongbat is hardly a challenge for a well-outfitted warrior, their use sheer numbers can easily overwhelm the ill-prepared.

Trivia

 * Considering the number of references to the The Wonderful Wizard of Oz throughout the Ultima series, mongbats may be based upon the winged monkeys from the same novel.
 * In the SNES Port of Ultima VII, mongbats hurl projectiles at their opponents, rather than engaging in hand-to-hand combat.
 * Mongbats were to be included in the cancelled Ultima X. See Planned Monsters for Ultima X: Mongbats for further details.