I was just flying around mam the island and then i find him on peaceful island i attacked him with my pteranodon with 1000 hp an he just only one attacked me and... Pteranodon-350hp i was like I WANT THAT TITAN!!!
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 ;)