UFC flyweight champ Demetrious "Mighty Mouse" Johnson is already working hard on his post-fighting career.

Playing video games.

Johnson's been streaming his gameplay to Twitch -- a video platform that allows players to watch others or to stream their own gameplay -- for a while now, getting in 15 hours a week or so under the username mightymouseufc125.

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Call it on-the-job training, because he's looking to go full-time when his UFC days are done. And laugh all you want, but know this; 1. He can almost certainly kick your butt; and 2. There's some real money to be made there.

One of the lesser-known aspects of eSports and pro gaming is that a lot of players rely on steady income from streaming their gameplay, as the big paydays at eSports events are rare (and not guaranteed). Popular streamers can make thousands per month, both in reveue sharing with Twitch and through donations from the people watching them play.

Johnson discussed it at length on the Three Amigos podcast (you can listen here or read the transcript at Bloody Elbow).

From the interview;

I heard you could watch people play videogames, and that's how I discovered Twitch. This is when I had Tyren, who is now two and a half years old. I would rock him to sleep at night, and he would take a while, so I downloaded the Twitch app to watch. I saw guys playing games I grew up with like Mega Man X and Zelda: Ocarina of Time. So after some time I started streaming some games on my PS4. I'd have like two viewers in there as I played Final Fantasy 14: A Realm Reborn.

Next thing you know, my wife was like, 'You should get into it baby, what do you want to do after you're done fighting? Why don't you try streaming?' Then Twitch reached out to me and told me everything I needed to get to be a serious streamer. All of the credit goes to my wife, she's the one who suggested I do it. I decided if I was going to do it, I had to be 100% in. I didn't want to do it half-assed and try to stream from my PS4 or Xbox One, so I bought a computer and she was all in, so I was like, 'Let's do it.'

Johnson isn't the only UFC star doing it either. Former light heavyeight champ Rampage Jackson streams under the name RAMPAGEishuman and is one of Johnson's frequent rivals.

On playing against Rampage, Johnson told the podcast;

There are other fighters who stream, like Max Holloway, Angela Hill and Rampage Jackson. Rampage and I kind of have a little duel going on. He likes to play Rainbow Six: Siege and every once in a while Team Rampage will play Mighty Squad and we'll double stream it and have a good time.

If you go by kills, I'm better than Rampage. I'm a beast, just to be honest. If you go with who has a higher rank and puts more time in, Rampage is better. It's one of his favorite games and he plays it a lot. It's not a Rambo style game, you board up a room and camp and wait for someone to come, then you shoot them.

The last time a game got my heart rate up was playing Rainbow Six against Rampage. I was actually sweating. My wife was watching, asking why I was so tense. I was like, 'Because I'm playing against Rampage with Mighty Squad! Reputations are on the line, baby!'

So tune in and check him out, if that's your thing. Who knows, you might even see a UFC drug tester show up midstream.

(h/t to Kotaku)