GoT: What was the name of the boy Arya was playing with (and who later died) when Nymeria attacked Joffrey?

Answer 1

Mycah
Mycah is a butcher's boy who Arya Stark befriends on the ride south from Winterfell to King's Landing. He sleeps in the meat wagon and smells accordingly. Just seeing him makes Sansa sick. Arya and Mycah start exploring together the lands through which the treck passes. Mycah shows Arya a lizard lion when they come through the Neck and, when they reach the Ruby Ford, they intend to search the Trident for rubies from the armor of Prince Rhaegar Targaryen.