The act of 'Prarie Dogging' with a 'Grogan' in one single move. That is, when your poo is still hanging on to your anal sphincter and simultaneously touches the water in the toilet bowl and you subsequently manage to suck the poo back into your anal canal. It is readily accepted as the "ultimate move" when taking a dump.
Holy ****! Dave! Come here man, I'm pretty sure I just shat a Grogan Prarie Dog! I slurped that sucker right back up!