Lybia edmondsoni is a species of small crab in the family Xanthidae and is endemic to the Hawaiian Islands.

The chelipeds are not heavily armoured as in most crab species but are fine and delicate, the propodal-carpal joint being very flexible, and there are several backward-pointing spines.

[2] The common name "pom-pom crab" comes from its symbiotic practice of brandishing a stinging sea anemone (usually Triactis producta) in each claw to defend against predators and possibly to stun prey.

[2] Lybia edmondsoni is endemic to Hawaii but is very similar in its size and behavior to its sister species, L. tessellata, which is much more widespread in the tropical Indo-Pacific.

It is also found on sandy and gravelly flats, where it is well camouflaged, and on live corals where it clings with its long, slender legs.

One crab was observed in the process of pulling an anemone in half by holding it with both its chelae and then drawing them apart until the tissues parted.

Advantages to the anemone may include being brought into contact with more food and oxygen than it would encounter if it were stationary and the avoidance of the risk of being submerged in shifting sediment.