When a person falls into a state of panic or crisis during the night. Usually triggered by one useless thought, the midnight crisis is common when the person is failing in trying to sleep.
Example of a midnight crisis
"Are you ok?"
"What am I doing with my life? Why am I here?"
"All I said was what did you do today"
Morning breath.
The story of the Midnight Moose is that it's a moose, who goes around at night taking dumps in people's mouths as they sleep. So when they wake up, they have bad breath.
Attempting anal intercourse with your sleeping partner.
Note - This can performed at anytime of the day, but has more signifance when perfomed in the mignight hour.
Reference - Midnight Express (1978) - American college student sentenced to life in jail in Turkey for trying to smuggle Hashish. During his time in prison is repeatedly sodomized by jailers.
I tried to catch the Midnight Express, but got a slap across the face instead.