Liverpool. They're a football team. You've heard of them. They compete in two of the most bitter rivalries in English football, they're from a place where they breed people pretty tough.
It takes something pretty special to be one of Anfield's hardest. So...
Having burst into the Premier League with West Ham, the Argentinian made a controversial impression after biting Jermaine Defoe's arm in one of his seven games for the Hammers. Mascherano went on to make 139 appearances for the Reds and was a real stalwart in their midfield.
Never afraid of a challenge, 'Jefecito', meaning 'Little Chief', was sent off three times in the Premier League, famously against Manchester United in 2008 after an altercation with Paul Scholes.
Also – and for some reason this wasn't in the original draft of this piece – he made an incredible goal-saving tackle on Arjen Robben in the World Cup semi-final in 2014. He later described the challenge thus: "
Another full-blooded central midfielder, Englishman Danny Murphy ensured his high status among Liverpool
More recently known for being a Match of the Day pundit, Mark Lawrenson is one of the biggest legends in Liverpool's history. Bought for a club record fee – at the time the most expensive British defender – Lawrenson went on to form a brilliant defensive partnership with Alan Hansen.
Not only did he live up to his potential, but became more than just a ferocious tackler with considerable skill and speed once he had the ball.
Oh, and he dislocated his shoulder three weeks before a European Cup final and started the game anyway. Much to learn for some younger players.
Currently one of the most engaging Sky Sports pundits and known for his entertaining debates with Gary Neville, the Reds defender had an immense career at Anfield; playing almost 20 years for the club.
Was he Liverpool's most skilful, talented player? No. Was there anyone in the squad who could match his sheer intensity and willingness to crash into other people at high speed for the badge? Also no.
The Scouse midfielder earned himself a reputation for tackles that connected more with player than ball – even allowing for the more relaxed refereeing standards of the 1980s.
That full-blooded approach to the tackle is perhaps why he's still received pretty well at both Goodison Park and Anfield, despite playing on both sides of the Merseyside rivalry. Winner of the FA Cup twice, the midfielder was labelled 'the Bully' on the pitch, although he only received two red cards in more than 200 games for the Reds.
Arguably the greatest player to ever play in front of the Kop, Gerrard is renowned for his sensational goalscoring from midfield and his ceaseless work rate.
Oh, and his willingness to absolutely go through anyone who got in his way. Or people who didn't get in his way. His seven red cards are the most for any Liverpool player in history, and that seems to be rubbing off on his players now that he's a manager. Rangers' Alfredo Morelos had been sent off four times by the end of February this season.
Voted inside the top 20 hardest footballers of all time in 2009, Neil 'Razor' Ruddock is...look, just don't cross him. Just don't.
His most famous moments include an infamous dust-up with Manchester United's Eric Cantona, breaking Peter Beardsley's jaw in a testimonial and leaving Andrew Cole with two broken legs in a reserve match.
More recently, he's appeared on ex-footballer weight loss programme
Known as the 'Anfield Iron' by Liverpool fans, Tommy Smith was at Anfield during both Bill Shankly and Bob Paisley's eras, where he won four league titles and the European Cup.
There was no doubt that he was a ferocious tackler, but Smith would frequently not only stand up to referees' decisions, but often berate and undermine their authority on the pitch. Bill Shankly summed up the one-time England international best: "Tommy Smith wasn't born, he was quarried."
That's right kids, a man with that moustache and those shorts could be considered one of the most fearsome living human men at one point in living memory.
Oh, and he almost sparked a riot in Turkey when managing Galatasaray, when he walked out into the centre circle and planted a big Gala flag into the ground. The ground of their Istanbul rivals Fenerbahce. Nerveless? Probably.