drop a dragon's goat
Take a dump.
"I really need to drop a dragon's goat."
"I haven't dropped a dragon's goat in awhile; I think I should see the doctor."
"I'll be out in a minute. I'm dropping a dragon's goat."
"I haven't dropped a dragon's goat in awhile; I think I should see the doctor."
"I'll be out in a minute. I'm dropping a dragon's goat."