Xysticus cristatus, the common crab spider, is a European spider from the family Thomisidae.
The adult female reaches a length of 8mm and the smaller male 5mm. The colour varies from light cream, dark brown to greyish with a dark triangle on the carapace which ends in sharp, defined point. The abdomen has a broad middle band fringed by two darker rows of triangular marks which extends back to about two thirds of the carapace length from the posterior row of eyes. This cryptic coloration is used to blend in with its normal environment of dried leaves. The common name crab spider arises because they sometimes move in a crab-like way, from side to side.
Xysticus cristatus is usually found in low vegetation, often on the ground. It is shade intolerant and avoids woodland and closed canopy habitats but it is otherwise found in almost every habitat type.