Mexichromis pusilla is a species of sea slug or dorid nudibranch, a marine gastropod mollusk in the family Chromodorididae.

[2][3] This nudibranch is found in the tropical Indo-Pacific Ocean.

[4] Mexichromis pusilla has a pink-orange body, gills and rhinophores.

The mantle is edged with a broad pale yellow band, and there are two white spots on its dorsum.

[4][5][6][7] This species can reach a total length of at least 20 mm,[4] and like all Chromodorids, feeds on sponges.