The 33-year-old actor - who will reprise his role as the Marvel superhero in 'Thor: Ragnarok' - was inspired after he surprised ailing youngsters at the Lady Cilento Children's Hospital in Brisbane, Australia.
Alongside a picture of himself and his co-star Tom Hiddleston - who plays Loki in the forthcoming film - he wrote: "Met the real superheroes of the world at @ladycilentochildrenshospital. A huge shout out to all the brave kids who are an inspiration to all of us! @twhiddleston #madepossiblebychf #ladycilentochildrenshospital #juicedtv (sic)"
One of the patients got to interview the pair for Juiced TV, a television show made for kids in hospital.
11-year-old Koen Weir asked Chris: "What is it like getting to be a superhero or supervillain?"
And the hunky star replied: "Well it's very cool, especially when I face with this supervillain.
"He's very mischevious and he's got lots of tricks up his sleeve so you've got to watch him. He's a bit shifty."
Tom Hiddleston - who was fully dressed in his all black Loki ensemble with long black hair - described meeting the youngsters as "unforgettable" and shared a quote from the movie.
Alongside a picture of himself and Chris with two patients with massive smiles on their faces, he wrote: "Whosoever holds this hammer, if he be worthy, shall possess the power of Thor!" (i.e. everyone but the weirdo in the black suit). Unforgettable meeting all the children @ladycilentochildrenshospital. They're the real heroes. #madepossiblebychf #juicedtv #ladycilentochildrenshospital (sic)"
Last month, Tom, 35, visited the same hospital with his girlfriend Taylor Swift.
A post on the medical facility's Facebook page read at the time: "Thank you Taylor Swift for dropping by the Lady Cilento Children's Hospital this afternoon to give our patients and families a special surprise they'll never forget. They'll never 'shake off' the memories you made tonight."