Just starting a new campaign with 6 new players:
DM (me): “You all arrive at a run down tavern in a swamp. The surrounding water is brackish and foul smelling-”
Our Tiefling Ranger: “I DRINK THE SWAMPWATER.”
DM: “…Okay, Roll a Constitution saving throw.”
Ranger: *rolls a 17*
DM: “You…somehow manage to keep it down.”