Arthur's Massive, Throbbing Hit
Arthur's Massive Throbbing Hit is a flash poop by WalrusGuy uploaded on August 8th, 2008. It was the most popular Arthur poop (and one of the most popular poops in general), and is the third poop to get a million views, behind Toys Gone Wild and Mickey Mouse's Wacky Poophouse Adventure (the latter of which has been panned universally on the YouChew forums).
The Arthur clips were taken from the season 4 episode "Arthur's Big Hit". Since its removal (caused by WalrusGuy's account being hacked), its popularity has been succeeded by "He Touched Me Inappropriately", which is now the second-most viewed seeing as how MMWPA was removed.