TreeTopia Ep 6 "GRIEFED!?" (Minecraft)
During the end of their first session, Kootra accidentally left the server out, letting anyone to play in it. Due to this, someone (Bobby) blew up all of their homes while they were away. Nova discovered this first (Opening of episode 6) and the problem was fixed immediately. Seamus found Bobby's house at the end of the jungle close to their in-progress treehouse village and Sly found a sign that said Bobby and was called Bobby Burglar after.
Bobby is frequently mentioned the episodes after, being blamed for unexplainable things (Such as a cave on the other island, that no one visited that was fully lit with torches)