I've always thought of Vessel as a slinky creature, almost like an arachnid. Likely because his name and traits kind-of remind me of the Weaver from the novel Perdido Street Station.

His "antennae" are tied together tightly, his "face" stretching a slight bit (as apparent on his neck), and some of the contents are leaking out (blood, that when falling, turns into dreams). Hehe :3

The Weaver was a giant spider-like creature from another dimension that the people had to negotiate with. Quite interesting.

The story didn't have a particularly happy ending :/ Not a story for a sunday afternoon, heh.