A skunk rolling down a hill with a pickle in its mouth.
It ran out of juice. I shall take my leave now.
Because he was dead
Gender rolls
Do they follow territorial boundaries? If the Kaos Kommandos start a brawl in El Paso and it rolls over into Juarez, do they say "screw it, let Justice League of Mexico handle it"? (Sorry if this isn't technically a joke; it was my shower thought this morning and I thought it was funny.)
Ventriloquists have to be able to speak with their mouths closed. Politicians speak out of both sides of their mouths simultaneously.
Both have big heads that consist mostly of mouth!
Something that stinks and stings!
Winnie the Pooh!
Pickles
Because the door was ajar!
