A Horse walks into a bar...

There is a ghost serving behind the bar. "Oh" said the horse; "I thought that I was the only implausible part of this joke."
"Well no I'm afraid you're not" replied the ghost; "though I do respect your ability to recognise yourself as being a fictional character in a joke." The horse thought about that for a moment.
"It's not a very good joke though is it?"
"I feel like it's bad form to criticise the joke within the joke itself." Said the ghost; "I think it's quite clever in a post-modern self-referential kind of way."
"I don't think so." Said the horse. "I think it's shit." He then left the bar and immediately hanged himself from the nearest lamp-post. The Ghost drifted outside to have a look. "Oh dear" he said to himself, "This is a depressing turn of events. I suppose this was always really a tragedy only ever masquerading as a comedy. The usual forms of story-telling are really being messed with today."
The ghost then began to furiously masturbate while staring directly at the horse's bloated corpse in the vain hope that it would provide some kind of serviceable punch-line.