The fastest way for your entire tribe to rage quit is to have one of these randomly spawn in the center of your base. Oh, that doesn't happen? Think again, literally just did. What the actual f*** Ark??!!!
Easily killable with a wyvern. Lightning and poison easiest down to longer range in attack. Just hover above and light it up :) killed my first today and it didn't touch me once. Just remember to watch stamina ;)