"Millerichthys" is a whimsical yet scientifically dubious Greek word, essentially a playful amalgamation of "miller" (referring to miller or miller fish, which is just a fish with a bizarrely named genus) and "ichthys" (meaning fish). So, imagine it's the fish equivalent of a quirky, mythical creature with a name that sounds like it came straight from the wild, yet is somehow scientifically plausible. It's like calling a school of rainbow-colored fish "Millerichthyuss," but with the added flair of having a name that sounds like it was conjured up by a mad scientist or a particularly enthusiastic kid in high school biology class.
Now, here's an edgy example sentence: "The Millerichthys of the abyss, with its bioluminescent tentacles and an appetite for deep-sea jellyfish, would make a perfect addition to any underwater horror movie, except when you're trying to impress your girlfriend."