Avengers stars Chris Hemsworth, Chris Evans and Mark Ruffalo each paid tribute to the child via social media.
To congratulate Bridger, the World Boxing Council sent him an "Honorary Champion" belt, and an image of the beaming youngster was shared to his aunt Nikki Walker's Instagram.
"We are honoured to name 6-year-old Bridger Walker, WBC Honorary Champion, for his brave actions that represent the best values of humanity," WBC tweeted. "Bridger, you're a hero."
Bridger's mum thanked her followers for all the messages of support received since the tragic incident.
"They told me they would send him a belt, but I didn't realize it would be THAT belt!" she posted alongside the image.
"The family and I spent much of the day opening the cards and packages Bridger has received. It's been such a surreal experience for us, because we recognise that each envelope and box represents an individual or family who used their time and resources to wish Bridger well.
"We wish that we could meet each one of you to thank you in person. Our hearts are filled to overflowing, and thank you hardly seems sufficient."
WBC President Mauricio Sulaiman also passed on a message of congratulations via Twitter.
Ruffalo was one of the first high-profile names to comment on Walker's story.
"People who put the wellbeings of others in front of themselves are the most heroic and thoughtful people I know," Ruffalo wrote.
"I truly respect and admire your courage and your heart. Real courage isn't dominating people or fighting against people or walking around like a tough guy. Real courage is knowing what is right to do and doing it even when it might end up hurting you somehow.
"You are more of a man than many, many I have seen or known."