Satan is a catfish.
Satan is a Texas catfish.
Satan eurystomus is better known as the "widemouth blindcat",
a type of eyeless albino catfish that lives deep in the ground (hypogean
or stygobitic), in the water filling the rock interstices of the deep
Edwards Aquifer under San Antonio, Texas. Feeding on any creature
it encounters in its underground travels, the widemouth blindcat is a top
predator that can grow up to 13.7 cm (about 5.5 inches) long. Lacking
eyes, it must detect its prey by sensing electrical disturbances with its
lateral line and barbels.
We know about this creature due to its being pumped, along with irrigation
water, from five Artesian wells around San Antonio. In 1938, Carl
L. Hubbs, an ichthyologist at La Jolla University near San Diego,
California, was invited to San Antonio's Witte Memorial Museum to view
several blind catfish which had been pumped out of nearby wells.
Carl Hubbs is a giant among ichthyologists, a prolific author on
fishy subjects. When he determined that one of the fish was
an unknown species, he gave it this whimsical name because its deep,
dark abode (or a somewhat drier version) was once thought to be the location
of Hell. The fish's somewhat repulsive appearance probably helped matters.
The Hubbs Story
Aldemaro Romero's Lab,
The above website gives a citation for the original paper naming the
Hubbs, C. L. & R. M. Bailey. 1947. Blind catfishes from artesian
waters of Texas.
Occasional Papers of the Museum of Zoology, University of Michigan
The Handbook of Texas Online