In Latin, “corvus” means crow. So the adjectival form used in biology for birds-such-as-crows is “corvid”. Sometimes people get confused in interesting ways.
Latin pedantry being what it is, the denizens of /r/crows are of course aware that a crow is in general called a corvid. So, what does one say when confronted with a picture of 18 crows? 
One opines that they are waiting for Corvid 19, of course.
Yeah, that’s it
I know: it’s pedantic, but I’m a pedant; it’s a “dad joke”, but I’m an old dude; it’s… well, what it is. That’s all I got.