Tranq Arrows/Darts DO NOT WORK!!! To knock this out you need to use a catapult and shoot in only on it's back. If you shoot it on it's legs it will kill it.
@Stormwebb19

To the guy who said "rare on floaty islands on crystal" that is a load of crap found 20 on 1 ISLAND!!!

Cannon balls discrease taming effeciency significantly! So for high tame level, always use boulders. Please let other people know! :)

Available at floating island caves in Crystal Isles.
They're very rare in there so be patient

Put a catapult on a paracer, bring a high health turtle (carbomemys), whistle attack with the turtle and when the crab hits it put it in passive so you can easily aim and hit him on the body. No weird engineering needed.

Guide to using Stego(s) as Swords:
1. Put Stego(s) on aggressive.
2. Pick them up using the Crab
3. Walk near target.
4.Enjoy

Jumps super high and can launch stegos ... two at a time RIP turrets lol

I understand that all the previous tips submitted were useful, but just in case it was not clear, hit the TOP OF THE CRAB, it will have a special animation if you hit it in the correct spot, and will take only a small amount of boulders to tame, even a high level. (Irrelevant with Cannons)

No one seems to have mentioned that karkinos can use tools, they just need a special type of tool: doedicurus, use a karkinos to pick up a tamed armadillo and walk around to rocks and the armadillo hits the rocks and keeps them stored, argies and quetz can do it to but they can only hold one and they don't spawn on abberation, not sure but if you transfer a beaver to abberation you might be able to use it and an armadillo at the same time to gather both rock and wood

Want an effective trap for the crab?
For about 300 stone and wood the youtuber Captain Fatdog will show you the cheapest and most effective trap

This tame is like the Rock elemental, but do not shoot it in the head. Shoot it right in the back of it's shell. Anywhere else will kill it fast.

They spawn in Genesis in several caves in the Lunar biome

Shown spider

If you're taming and its health is low, put a corpse beside it. That should do the trick to heal it

If you are missing with your catapult and it's dying, drag dino corpses to it and let the karkinos eat the corpses. It will heal him up a lot then try again with the same torpor you left off with.

When playing aberration I found that these guys are a good rock drake egg thief. The can jump and are immune to the radiation. They are great fighters so I recommend you use these guys as a rock drake thief 👍👍👍

If you're carrying a tamed Doedicurus in your claw the Doedic will automatically start harvesting any stones you hover him over. Just start pumping points into your Doedic's weight because it will stop at about half of its own carry weight. I've yet to discover another tame it will work with though...

It's a Giant crab that can throw it's enemies far away

Be careful when carrying a Dino that has a tribe mate mounted on it. I was walking up a hill carrying my anky with a tribe mate on it and they went under the map and died. RIP ANKY AND SHINEHORN. Tribemate was eh anyway.

Best raider ever, a catapult a rex a prison and a parachute/glider launcher all in one