https://www.teepublic.com/t-shirt/2378052-372-pages-hell-of-a-rig-inflatable-cow
Basically the podcast is about making fun of Ernest Cline's Ready Player One and Armada. At one point the term "Hell of a rig" is used in Ready Player One, and that got Nelson's cohost to go off on a tangent about a time he saw an album of photos where a guy put on an inflation costume. One of the commenters advised the guy that he shouldn't have included the photos that revealed it was a man inside the costume but concluded "but anyway, that's a hell of a rig." I forget which episode.
I like that drawing :)