Late Tuesday night Austin's mother and her boyfriend began arguing over money. Austin says Shean Gilkey started to hit his mother and slammed her up against a group of bikes. Her blood can still be seen spattered on the wall from the blow.
The 5th grader picked up the phone and dialed 911, alerting police of what was happening. But this little hero wasn't done yet.
"I started yelling stop and he started choking my mom, so I kinda grabbed his fingers and pulled them back away from my mom's throat and I started kicking them," said Mundy.
Minutes later, police showed up and say Gilkey lunged at them, before he was arrested at gunpoint.
Austin's mother lay bloodied and bruised, but alive, thanks in no small part to her son. A little boy with a big heart, strong will, and a pretty pleased grandmother.
"Very proud, very proud. It's a scary thing wasn't it, seeing something like that go on, so he did real good," said Austin's grandmother, Mildred Gottschalk.
When asked how much he loved his mom, Austin responded "if it was on a scale it would be max and past."
His self proclaimed best friend in the whole wide world, whom he can't wait to hang out with again, as soon as she gets better.
"I'm gonna give her a gigantic hug and I'm gonna say nice to see you mamma, I love you so much," said Mundy.
Twenty-five-year-old Shean Gilkey faces a slew of charges including strangulation and battery. He remains at the Marion County Jail in Indianapolis.