Among the lucky few was 7-year-old Ethan Miller, who suffers from the rare blood disease ITP and type 1 diabetes. Ethan donned his favorite Avengers' signature red suit as he took pictures with Downey in fierce matching poses (above).
The actor also posed with an adorable baby Batman, a Disney-loving cutie, and a sweet young boy in a "Central Park" tee.
Downey is no stranger to a good deed: He recently posed with U.S. Marines while on a press tour to Berlin, and last year he dressed up as Tiger to invite a young fan suffering from cystic fibrosis to the LA premiere of Captain America: Civil War.
Look who just joined #teamironman / #teamstark the US Ambassador to BERLIN Mr. Emerson and the US MARINES security guard detachment BERLIN !!! #inyourface #teamtoy I mean #teamtoast I mean #teamcap #civilwar #Berlin #presstour representing @marvel Don't forget to click the link in my bio for a chance to hang with me in NYC!!
His character may be made of metal, but this actor is a softie at heart.