He's offering to draw people as a worm for a fiver (NZD currency here but I'm sure exact amount isn't too important):
https://www.instagram.com/p/C-JPWdry9aq/

He has played Worms, but not for decades, so more just a worm in his style. Here's his worm drawing of himself:

Me as a worm. He asked which band shirt wormy me would be wearing, so I figured it'd be the one of the band that inspired my wormy song.

Haha this is amazing