Is there such a thing?

[Tahn]

As a black devil?

https://newjersey.craigslist.org/for/6161162745.html

 

[Hendre]

Amphilophus sagittae, black morph. Apparently the black ones are simply the amphs that didn't morph into reds or yellows or whatever

 

[duanes]

Agree with Henfre, the term "_ devil" is a catchall term for what may be about 20 species of Amphilophus from the great lakes of Nicaragua. There are those with stripes, mottled red, yellow, black, grey , white, whatever it is a group of very variable individuals with the genus.
Amphillophus "amarillo" (spanish for yellow) with stripes

Amphillophus flaveolus below