Bring Therizinos instead of Rex’s, since herbivores take reduced damage from the fire, and can eat sweet vegetable cakes to regen health quickly. Take about 17-18 theriz, 2 hell pigs, and 1 yuty as well as an OP rocket launcher or shotgun, or substitute 4 theriz for allo’s to get the bleed attack.
Use as many therizinos as you want since it does extra damage to carnivores technically since the therizino is an omnivore which means carnivore and herbivore put together so since the other half is herbivore it should block out that affect I would also recommend pumping damage and health. Thanks for using your time on my tip I hope it helps you beat the boss.
To whoever said this is only hard to kill on alpha difficulty and wyverns are more powerful than this: a level 1 gamma dragon has 432,000 health and deals 500 damage with its melee attack. A level 1 wyvern has 1,725 health and deals 80 damage with its melee attack.