SE has most mantises but all are usually low levels, ragna has more common high levels and horns are easy to get from worm cave. SE has low lags and more color options during event, ragna has megalags and mana abusers that will mess up taming.
The mantis has two attacks, the close range hack and slash, as well as a devastating pounce. The pounce attack is long range and does considerably more damage than the hack and slash. Mantis aggro from a considerable distance (as in, if your on foot get out of there fast) so the pounce attack is very deadly. However, fire damage weapons i.e. Wyvern fire, flamethrower etc. do more damage than other rounds, the same goes for other insect/arachnid creatures
They drop organic polymer which can be used for ghille armor. Ran into 2 as I was leaving a cave and barely killed them using a pike. Dont ever let your guard down in caves, even when leaving and it was empty before