A post-AC commission. Here's the description as written up by the customer:

This picture takes a little explanation. It's an illustration of Whistler, from "Animals of Farthing Wood", meeting the Warden, from the Redwall novel "Martin the Warrior". Whistler's a genteel, helpful British-gentleman sort of fellow, and a Grey Heron. The Warden, a Great Blue Heron, fancies himself a medieval Judge Dredd -- quite literally. This was the result. Comissioned by  ArchTeryx at Anthrocon, 2011.

Done with markers.