a 'mop' is a cleaning tool used in wiping or washing the floor. so such skeleton will definitely spill the beer on the floor as it will literally wont't stay inside his body but just cascade down through his entire bone structure. afterwards, he'll wipe out what he had spilt. I think the catching part here is that the skeleton must be a "responsible drinker". :)

A mop is used to clean up fluid on the floor and as a skeleton has no skin or body he can't drink so instead of going into his bladder it will go straight through him

i hate tuvalu

wow...this joke is nice...i also didnt know the meaning...thanks romulus!

good answer amigo!!! 1 for you esse!! cowboy...