There's an area on scorched earth at around 5 Lat, 15 Lon where there are lots and lots of deathworms, so if go there if you need lots of horns. Be warned though, there are A LOT!

If you are to fight a death worm use a poison wyvern to damage it from far away

Don't walk on the ground fly and shoot with gun or crossbow

Use good shotgun run through it in mins

Wyverns all the way. I use a lighting wyvern with only 7k health and I still rekt them.

Get a decent fire or lightning wyv and your golden

Megatherium 5k hp 800mele and enter rage

All you’ve got to do is send in a raptor army and you’re good.

Where is in crystal isles???? Need for tamming mantis

Eeeeewwwggtthhg it's hideous!!!

If you are new and think these are bad, dont worry. A decent pack of mate boosted wolves works great. I used 4, and R. I. P. Deathworm

All you need is a oil jar, and to know where it is. Find the worm, throw the jar at the ground in front of it, then move backwards while keeping its aggression, that will kill it.

Use a lightning wyvern and regenerate stamina far away then snipe at it from the sky

These things get WRECKED by Velonasaurs. Just saying. (I know they’re two different maps but in case you play on a cluster, use Velonasaurs.)

To kill it easily... take you high level/OP lightning wyvern and hit it with the breath while flying. This makes it so the deathworm can't hit you and it'll most likely stay above ground since your close enough... at least that's how I killed one easily

Mid to high level wyverns annihilate these guys. Just swoop in and out while biting and breathing elemental breath on them

Using a mana in the lost island desert is a good way to farm deathworm horns. Just freeze them as they come out of the ground then jump out of the way before they hit you. Rinse and repeat and soon you have a dead deathworm

Go tame a couple thylacoleo breed them and then take 5 or 6 with you on the hunt. 100% imprinted thyla pack will shred deathworms in seconds.