G.O.L.E.M, Jr.
Quest reward from Showdown in the Attic. was a quest reward from but I haven't received it either upon completion or in mail box.
The 
G.O.L.E.M, Jr. is a toy obtained as a reward from the quest Showdown in the Attic in The War Within expansion.
Guide awaiting review
Complete Showdown in the Attic
Complete the quest Showdown in the Attic to receive G.O.L.E.M, Jr. as a reward. If the toy does not appear in your inventory upon completion, check your in-game mailbox, as several players have reported not receiving it immediately.
Tips
Using the toy transforms you into a G.O.L.E.M, and the paint color changes each time you activate it.
The transformation persists through combat but will break when you mount up, resuming once you dismount.
G.O.L.E.M, Jr. can only be used in Undermine.
