A good and reliable strategy for fighting this boss is to get a high health soaker such as a stego and a velonasaur.

Have the stego distract the boss as you shoot it in the eye with the velo.

This will still take a long while so your stego better have high health and your velo high stamina and food.

Thodes is a cyclops on astreos, he is one of the final bosses, and needs to be shot in the face to allow him to take damage.

Do not forget your ammo when you go into this boss fight, you will lose everything

I think he is a boss on Astreos