Dog says he first heard about this case through a mutual friend of the victim. The alleged beating occurred in Las Vegas, but multiple reports say the suspect fled to San Diego and continues to move.
Now Dog has vowed to find War Machine, the mixed-martial-arts fighter, who is accused of beating his porn star girlfriend, Christy Mack.
Las Vegas police are searching for War Machine, but Dog says he's days away from coming face-to-face with the professional fighter who's on the run.
"Time is up! Beware of the dog," Dog tweeted.
Eyewitness News spoke to Dog on the phone Wednesday night from an undisclosed location.
"This is a killer, this is not an average guy," Dog said.
Jonathan Koppenhaver legally changed his name to War Machine. Police say he showed up to the home of his girlfriend Christy Mack Friday night, beat up her male friend and then started punching her.
Mack posted photos to Twitter, saying he broke 18 of her bones, fractured her rib and ruptured her liver.
"He fought her like a man," Dog said. "Her blood was flying all over the room, all over his face and even in his mouth, and she said, 'Dog, there was no referee to stop it.'"
War Machine is still on probation from a 2010 fight at a Pacific Beach bar. He plead guilty to assault.
"I'm not a bad person," he told the judge. "Every time I get in trouble, it's because I'm in a bad environment."
Now, War Machine is on the run, but continues to tweet.
"I'm not a bad guy, I went to surprise my gf, help her set up her show and to give her an engagement ring and ended up fighting for my life," he tweeted.
Dog said he is following tons of leads.
"Leads are coming in like Obama had votes, I'm telling you. It's just incredible. I'm charging my phone, I probably have to charge it four times a day just on leads, bling, bling, bling," Dog said.