Define Tiger In The Bathroom Meaning

Tiger In The Bathroom
When you were so drunk last night and you wake up with a big hangover, you almost can't remember what happened last night.

Courtesy "Hangover, The Movie"

Jim: Men, I have like the worst hangover
Ron: You were pretty knocked out last night. Did you find a tiger in the bathroom this morning?
Jim: Almost. If I'd had 1 more tequilla yesterday, I definitely would have seen that tiger
By Ilysa