Tony Stark takes no days off. "Iron Man" star Robert Downey Jr. surprised a 7-year-old boy, Alex, with a bionic arm made from a 3D printer. After they both tried their respective Iron Man arms on (they're seriously awesome), Downey and his young counterpart engaged in an epic fist bump. It's almost too much. Almost.
![See Robert Downey Jr. Give 'Iron Man' Bionic Arm to Boy with No Arm]()
