From Mike Tyson to Floyd Mayweather to Tyson Fury, the involvement of celebrities at WWE events has been the norm for decades.
Such is the popularity of WWE and its unique blend of sports and entertainment, it is only natural that it has gained a huge following all around the world - with celebrities being a big part of it.
From those who grew up watching the product themselves to those who just know a good business opportunity when it presents itself, the lure to appear on WWE programming has proved too strong for a string of big names over the years.
From cameo roles to major matches, celebrity involvement at big WWE events has taken all forms - most notably of course at the company's biggest event of the year, WrestleMania.
The whole idea of the very first WrestleMania was, of course, to gain mainstream attention for WWE, and the involvement of the likes of Mr. T from the A-Team back in 1985 did that job superbly.
In the 35 WrestleManias that have followed - plus other pay per views and RAW and SmackDown on television, we've been treated to plenty of memorable moments featuring major names who hadn't established themselves in WWE to find their fame.
Here, we take a look at five times major celebrities grabbed the headlines at WWE events:
#5. Floyd Mayweather Jr
Floyd Mayweather Jr was undoubtedly the biggest name in boxing for a generation when he made the switch - albeit temporarily - to become a WWE Superstar ahead of WrestleMania 24.
'Money' Mayweather took on the mammoth Big Show in Orlando, Florida, in a hard-hitting no disqualification match. It's interesting to note, however, that Mayweather didn't just turn up for 'Mania and do a few minutes' work for his payday - he actually did plenty of work in building the feud before the show.
At No Way Out, one of the events before WrestleMania, he aided good friend, Rey Mysterio, from a post-match beat-down by Big Show. The boxer turned the tables and left the seven-footer laying instead.
Mayweather then appeared at RAW shows in the build-up to WrestleMania and was there for a 'weigh-in', too.