I used a crab since they dont seem to aggro to them. Just dropped the egg near it, hopped off for a second and back on the crab again to get it out of the ground and it slithered around till it was hungry enough to eat the egg. Kill everything around it aswell
Seems like raising a rock drake 1st will help you tame these. 1st raise a drake. 2nd collect a bunch of rock drake eggs. 3rd find a basilisk and while riding the cloaked drake drop the eggs one by one and it will eat them.
Actually the Basilisk only eats Rock Drake fertilized eggs. The wiki says that it should also eat other fertilized eggs, but currently it ignore them. Probably it's a bug, for now feed it Rock Drake eggs