Someone who goes for a number two at exactly the same time every day. They are so punctual that EVERYONE knows where they've gone!
Person 1: Abel is such a punctunal-pooper!
Person 2: i know blud, i swear mans could set their watch with him.
Person 1: Where's Abel gone.
Person 2: You know where blud!...it's 14:30!
Person 1: That dude is such a punctual-pooper.