Hydrae (U6)

Encountered only in Ultima VI, the carnivorous hydra is a hostile plant native to the swamplands of Britannia.

Description
Possessing a central, mouth-like structure from which numerous tentacles radiate to strike at nearby threats, this plant is a serious menace. Creatures are either killed and then dragged to the maw for feedding, or are simply eaten alive right away. Needless to say the presence of such a plant makes expeditions into swampland highly dangerous, though due to their immobility, distance attacks are a safe way to get rid of them.

Curiously, this aggressive bit of flora shares its name with the multi-headed hydra seen in Ultima IV and Ultima VII. The reason for that is unknown.

The Ultima 6 Project
Due to the confusion that arose in Ultima VI from this suddenly appearing (and after the game again disappearing) monster and its name, the designers of the Ultima 6 Project decided to replace these plants with the much-more known, normal dragon-like hydrae.