This 3" Gobiesox maeandricus (Northern Clingfish) was hiding under a rock during the minus tide.
Point fermin tidepools
Clingfishes are fishes of the family Gobiesocidae, belonging to the order Gobiesociformes. Most species are marine, being found in shallow waters of the Atlantic, Pacific and Indian Oceans. They are bottom-dwelling fishes; some species shelter in sea urchins or crinoids.