A member of the Evil Horde, Leech is amphibian with a bulky build and suction pads on his hands, feet and mouth, which allow him to drain the life-force from his foes, rendering them helpless against him.

Leech as he appeared in the Masters of the Universe Mini Comic

As a humanoid leech-man and member of the Evil Horde, Leech was a deadly and loathsome creature. His slimy green lips and suction-cupped hands could envelop his victims and drain their energy. It appeared that Leech could even do this with vehicles, as he once completely drained the Land Shark of power. Leech could also use his suction ability to destroy obstacles in his path.

Leech as he appeared in the She-Ra and the Princess of Power Cartoon

A product of Horde science, Leech was one of the most grotesque members of the Evil Horde. He thrived on terrorizing Etherian villagers and was often seen licking his lips with his enormous tongue or clapping his slimy hands in delight. He was capable of remaining underwater for extended periods and could transform his hands into suction cups that drained the energy from his enemies.

Wiki Grayskull History

According to the Wiki Grayskull, Leech was introduced into the Mastersof the Universe toyline in 1985, among the first wave of Evil Horde figures. His figure was packaged with the minicomic “Leech: The Master of Power Suction Unleashed!”[1] It has large flat hands and a mouth which is a rubber suction cup, and can actually stick to flat smooth surfaces for short times if lightly moistened. This minicomic presents him as an immense sea monster summoned from the ocean depths by Hordak to fight against He-Man and the Heroic Warriors. A terrified Mer-Man also appears, with an unusual likeness: he has a bright red face and a black beard.
Leech appears in animated form in She-Ra: Princess of Power, in which the Horde are the main villains. He is regularly seen among the main Horde members, but rarely showcases his power suction ability and receives generally little character development and no episodes feature him in a spotlight role