Rich Horwitz has to have one of the creepiest jobs around.

The fisheries scientist at the Academy of Natural Sciences knows all about the the snakehead fish that first showed its pointy head and siky grin in FDR Park in 2004. Dubbed a "Frankenfish," it's ugly and it gobbles down native species.

Then there's the flathead catfish, another species that's not supposed to be here, but that has thrived in the Schuylkill River.

And more.

Horwitz is going to give a fishy virtual tour at a "Science on Tap" session Monday at National Mechanics, a bar in Old City that hosts the monthly science cafe.

He'll give an informal presentation on "Shocking Streams and Freaky Fish."  Here's the description from the science tapsters: "Alien invaders. Deadly river monsters. Fish infused with chemical toxins. All these and more swim a few miles from Center City."

The adventure begins at 6 p.m.