So... is there a rare creature rate?

[agenevil]

I would like to know how many times to expect to start temple.

[Ketchup345]

No official rate.

Average accoring to some people's excavation reorts is around 1/512. 1/512 has been used as the unofficial rate for quite a while.

[zwandude15]

From personal experience, I've used the 1/512 rate as well. But I will often find a rare enemy around 1/300 mainly based on number of pipes times the number of enemies being used.