Quark and the Mosquitos (1987)

In the fourth of a series of cartoons featuring Quark, the ugly troll from Valhalla (1986), Quark finds himself in the company of viking-like villagers. When Quark eats the last of their magic mushrooms, they send him to the woods to find more, but what he finds is troubles with the animals of the forest, including a flying army of mosquitos.