Morth

Morths are small, spiky, spherical, parasitic Mothula larvae that always appear in groups. They cannot harm Link directly, but they weigh him down by clinging to his body.

The Legend of Zelda: The Wind Waker
In The Legend of Zelda: The Wind Waker, Morths appear primarily in forested areas, such as the Forbidden Woods and the Forest of Fairies. They can appear automatically in a room or be spawned by a Mothula. They tend to appear in large swarms, staying perfectly still until Link approaches, at which point they will attempt to cover him. A single Morth will barely weigh Link down at all, but a large amount of Morths will slow him as though he is wearing the Iron Boots. They can scurry along the ground or hop a short distance, and are light enough to float on the surface of water. They can be easily defeated with most weapons, particularly the boomerang, though if Link uses the Deku Leaf on a group of them they will scatter all over the room, gently floating to the ground. When they are on Link, rolling works to knock them off a few at a time, while Spin Attacking can defeat them at the same time.

The Legend of Zelda: Tri Force Heroes
In The Legend of Zelda: Tri Force Heroes, trios of Morths appear without Mothulas and are now depicted as primarily desert creatures, first appearing at Gibdo Mausoleum. They burrow up from specific places the sand, respawning if defeated. The three Morths always act as a unit, pursuing and attaching to one Link. Due to commonly being found around quicksand, they can force a Link to sink from the added weight. Additionally, an affected Link cannot dash or rid himself of attached Morths, so instead another Link must attack them. When they appear in levels requiring all enemies to be defeated, they are not counted in the total due to respawning.