Valguero Taming Guide: Mantises spawn at the bottom of the Wyvern Scar. To tame them, first you will need to go to Scorched Earth and wall around the North, West, and South deserts at the perimeter of the map. Each circuit around the map should give you 5-10 horns. Horns can be collected from Iceworms in Ragnarok as well.
Once you have your horns, equip a full ghillie suit and bug repellant. Approach the scar from the East, and you should see two cliff platforms in the snow at the entrance to the Scar. There will almost always be several Mantises on the ramp descending into the scar along with dung beetles, titanaboas, and arthros.
Clear the trash, agro a mantis, and run back up the ramp and onto the snow platforms. Mantis should lose agro on the platforms, and you can then start taming peacefully. Approach from behind with your ghillie suit and bug repllant, passive tame with the horns and feed every 3 minutes. Voila, easy Mantis. I tamed 4 in less than 2 hours like this.
Best method I was told. Build a 2x2 stone [or wood if low] foundation with 2 high walls, drop in with flyer, feed through wall. Has a massive hitbox to feed it through if lured close to a wall. No repel needed with this method.