I’m pretty sure this is my first attempt at drawing a character with a neck-beard.
Here we see Agatho putting a stone in his mouth to remind him to keep quiet.¬† My guess is that he put a pebble in his mouth, but since comics are a visual medium, I changed the pebble into a brick-like rock.¬† It’s funnier to look at and also gives a nod to George Herriman’s Krazy Kat strips.