If one of these spawns in your base, have one of your tribe members leave the tribe and unclaim a flier, have them claim it, then fly it and lead it away. If no one is in your tribe, give up because theres nothing you can do.
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 ;)