Early reputation rests on shrubs revealing a class of creepers? (8)

I believe the answer is:
reptilia
'class of creepers?' is the definition.
'Reptilia' can be an answer for 'class' (Reptilia is an example). I am not sure about the 'of creepers?' bit.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for reptilia that I've seen before include "Class of cold-blooded animals" , "Class including lizards" .)
