The widemouth blindcat (Satan eurystomus) is a species of North American freshwater catfish endemic to Texas in the United States.

The eye remnants are extremely reduced in size with very little or no trace of a retina or lens; the optic tract is present, but always regresses before reaching the brain.

The swim bladder in these fish is reduced, and the skull is mostly cartilaginous and not well-ossified, unlike the adults of most larger ictalurids.

This species also has a few paedomorphic traits (indicated by small size, kidney morphology, and weak ossification of the skeleton).

[4] The widemouth blindcat's closest relative is the much larger flathead catfish (Pylodictis olivaris).