WATCH: Alex Pereira almost punches son during a prank gone wrong

Do not mess with the former UFC middleweight champion.

Alex Pereira's teenage son nearly saw the tail end of one of his devastating punches recently when he pulled a prank on his dad that almost turned dangerous. In the video one of Pereira's sons is at the top of the stairs filming as his father enters the dark home. Around the corner one of his other son's is waiting dressed in a mask and costume ready to pop out and scare him.

Unfortunately, instead of getting scared, Pereira got into fight mode and raised his fist ready to strike. Thankfully the son upstairs called down to his father and the other son fell to the floor in fear.

Watch the moment below.

It's all fun and games now but imagine what would have happened if Pereira had actually landed? We've all seen what he does to his opponents in the Octagon.

Alex Pereira and Anthony Smith are in a heated battle of words

Pereira recently transitioned from middleweight to light heavyweight where he made his debut on July 29. He defeated the former 205-pound champion Jan Błachowicz via split decision.

After the fight, fellow 205er Anthony Smith sparked anger in Pereira when he said he wasn't the "large scary monster" anymore.

Pereira then went after Smith calling him "washed up" on his YouTube channel. Those comments incited Smith to respond explaining that he hadn't meant anything negative by the comments.

“I said a bunch of nice sh*t about you, and you’re going to talk sh*t? I don’t think so,” Smith said on his radio show. “That’s not how this works. Then we’re just going to shake hands when we see each other because you’re doing this media thing because you’re looking for a rival? If you want a f*cking rival, you’ve got one right here. I didn’t do sh*t to you.