Conversation so far:
What is Vortex and Ed the Happy Clown?
Brown began to weave together some of the earlier unrelated strips into an ongoing surreal black comedy called Ed the Happy Clown. Vortex is a comic book publisher
When did Ed the Happy Clown start?
Brown first serialized it in his comic book Yummy Fur, and the first, incomplete collected edition in 1989
When did Ed the Happy Clown end?
He brought Ed to an abrupt end in Yummy Fur #18 to turn to autobiography.

Question: Did Brown collaborate with anyone on the comics?
Self-contained rewrite: Did Brown collaborate with anyone on the comics?