Whatever you do, do not get close to it with pretty much any medium dinos or fliers because these thing can pick up fricking argies and monch them to death so keep a good distance between them, you and your tames. Trust me on this i lost a lot of things to these monsters.
When i was exploring the island map i saw the chitin cave. I wasn't ready for the cave and i had to run out because i ran past 3 of these things. Good thing it was daytime. Go in the chitin cave during the day just saying
Can be found in Carno island cave, south west lava cave, south east cave near Stonehenge, Central cave near volcano, and possibly others. They are very rare spawns but if checked regularly you can encounter them if looking to tame.