Walt swoop down towards the entrance to the Hall of Justice as a bald eagle and upon landing on the ground, he shape-shifted back into his human form to quickly head into the head quarters of the Justice League. His mentor Animal Man fallowed close behind, and normally Walt would have let Animal Man take the lead but he was too excited for some of his formalities.
"Remember Walt, try to not let your wild personality get the better of you" his mentor told him, and Walt quickly nodded. Even if he did try to not act looney, Walt would probably fail at the attempt and he was too excited for getting to be a part of a team heroes around his age. He walked into the building and noticed Robin who was the famous sidekick of Batman. He moved over to Robin and smiled.
"Hello, the name's Shifter and as the name implies, I can turn into tons of different thing" he said to the Boy Wonder, and as he was speaking he transformed into several different things such as a tiger, then a refrigerator and finally Batman. Even though he looked exactly like the Dark Knight, Walt had none of the hero's incredible skills.
"Do you think a billionaire who saw his parents die and dresses up as a giant bat to go around and beat up criminal is completely sane?" He then turned back into his normal form and laughed, he hoped that Robin liked his jokey personality.