Annelid

The Annelids also known colloquially as Worms are a species of diminutive bipeds native to Takwalla.

Biology
They have two main arms, and also several small, stubby arms on their chest (six in the movies, but only two in the animated series). On their heads are two antennae. Their legs have two joints, a knee and another lower joint, and their feet have three toes each. They do not have spines, and they can pull their bodies together after being cut in half. Seeing they can do this, they might be able to regenerate.

Culture
Not much is known about their culture on their homeworld, but living on the homeworld of the human race includes a lack of oversight from the race’s emperor. Most Worm Aliens venture on hedonistic binges partaking in vices that are forbidden on their home world.

Men in Black
In the original film, the worms convince Agent J that aliens do exist. They are seen drinking coffee. They are later seen on their way out of the MiB building presumably to leave the planet with their luggage since they fear Earth is about to be destroyed.

Men in Black: The Series
Like the first movie, the Worms hang out in the MiB break room drinking coffee. They occasionally help Agents K or J with their work. There are some episodes that primarily focus on the Worms. Their obsession with coffee often gets them into trouble. In several episodes they sneak out of MiB headquarters and accompany J and K as blind passengers, mostly due to misunderstandings involving coffee. The worms have helped Jay on several occasions to take headquarters back after an invasion. In the episode "The Future's So Bright Syndrome" the alternate future shows the worms as the dominant race after the worms got slimed and multiplied. In one episode, one of the worms gets kidnapped by the Fmecks, because they mistake him for an alien scientist who has invented a growth serum. The worm gets later rescued by J and K, but he mistakes the growth serum for coffee and grows to the size of a tall building. In the episode " The Worm Guy Syndrome" J and Wormy start becoming mutated versions of each other.

Men in Black II
In the second film, they have a much bigger role. They watch after Laura, and they help infiltrate MiB Headquarters to stop Serleena.

Men in Black II: Alien Escape
In this game the worms are all over the levels, if you touch them they will give 100 points.

Men in Black III
In Men In Black III, The Worms are primarily seen playing the bagpipes at Agent Zed's funeral. They are shown again in the background pulling suitcases through the lobby of MIB headquarters when the Boglodites are invading Earth.

Men in Black: Alien Crisis

 * A pair of worms is featured on the cover art for MIB: Alien Crisis.

Known individuals

 * Neeble
 * Geeble
 * Sleeble
 * Mannix
 * Emperor Worm

Trivia

 * The name "Annelids" would likely indicate that their bodies are internally segmented, at least to some degree. The name comes from the scientific class of worms that includes bristleworms, ragworms, Bobbitt worms, tubeworms, boneworms, spaghetti worms, Pompeii worms, lugworms, methane ice worms, Tomopteris, sea mice, pigbutt worms (yes, that's a real animal...), earthworms, redworms, blackworms, whiteworms, ice worms, sludge worms and leeches; all of which are characterized by segmentation (although leeches have mostly lost theirs) and a collagen-based cuticle protecting their bodies. Depending on the classification you use, spoon worms and peanut worms may also be considered annelids, although they're not segmented.