Put a sleeping bag outside before going in this wyvern cave. It’s in the desert and trust me, it’s a suicide mission. I suggest bring a Pterodactyl and not an Agry, Agrys are fast but not pterodactyl fast, bring a fast-low level-pterodactyl and pray that you wont die. There is also a Griffin Ravine near the wyvern cave in the desert so be careful.

-hope this helped