Doubt this is going to be accepted

When the joke is so dark

It starts escaping the fields

When the joke so dark police shoot it

When a joke so dark, the police take it's breath away.

when the joke is so dark it gets whipped with a rope as long as the earth has existed

When the joke so dark

It's sold in black markets
(Double whammy)

when the joke is so dark that a Jews breath is gone

When the joke is so dark

The water starts going away

When the joke is so dark

Mysterious people in ghost costumes suddenly appear