Newt Scamander
From Tardis Wiki, the free Doctor Who reference
Newt Scamander was a man who once captured Beast Boy inside of his briefcase in the Land of Ooo. (NOTVALID: New Adventures Await!)
Behind the scenes
Newt is played in the Fantastic Beasts film series by Eddie Redmayne, who also provided his voice in LEGO Dimensions. Newt does not have any vocal interactions with an DWU elements within the game, however.
Redmayne was also in costume as Newt whilst playing himself in Looking for Pudsey.