"The bigger they are the harder they fall." That's the sort of rubbish rugby coaches like to spout when you're staring in terror at some giant on the opposite team.
All you're thinking is "the bigger they are, the much more painful it will be when they run into my face."
There's no denying some of the World Cup players are absolute animals. But which animal would they be? Here are a few suggestions...
Devin Toner
Devin Toner - actual giant
You wouldn't try and snatch a rugby ball off a Grizzly Bear, so don't attempt it with Ireland's Devin Toner.
Standing 6'10" (208 cm) without heels, he's one of the tallest players at the World Cup - and could go eye-to-eye with a grizzly on its hind legs.
While we'd take Devin's skills over the bear at the lineout, the Irishman's ability to catch a leaping salmon in his mouth remains unproven at international level.
Nemani Nodolo
Nemani Nodolo - shouldn't be allowed to be so big and fast
127 kg (20 stone) and feet like a ballerina. But obviously not an actual ballerina. Fiji's Nodolo is the biggest wing in world rugby and puts even the legendary Jonah Lomu in the shade. And that's quite a shadow.
Here's a tip if trying to knock him over. Former Aussie prop Matt Dunning says "he runs like a chicken but is faster than a lion."
Best try and tackle him round the legs then - but don't go near him dressed as a gazelle.
Uini Atonio
Uini Atonio - not technically a six-pack
France's Atonio is the heaviest player at the World Cup. 145 kg (23 stone) of mostly solid muscle. But how heavy is that?
Well imagine trying to bench press a Giant Panda.
That's exactly how it would feel lifting Uini - but without the need to constantly feed him bamboo or worry about him successfully reproducing in captivity.
Leroy Atalifo
Leroy Atalifo - wide as he is tall
Atalifo is another Fijian and stands at a very modest 5'10" (178 cm) - which backs up the old phrase about rugby being "a game for all sizes."
Nonsense. He still weighs 130 kg (20 stone) and being hit by him must feel like running into a bison wearing full body armour.
Similar to the Rhinoceros beetle, his size hides his incredible strength.
Another thing they have in common is the beetle likes battling other males - although the wearing of huge horns on your head at scrum time is currently frowned upon by the game's lawmakers.
Follow @BBCNewsbeat, external on Twitter, BBCNewsbeat, external on Instagram and Radio1Newsbeat, external on YouTube and you can now follow BBC_Newsbeat on Snapchat
