Like spring baby with a nature that’s wild (7)
I believe the answer is:
taurean
'like spring baby' is the definition.
(the star sign of a spring baby might be Taurus)
'with a nature that's wild' is the wordplay.
'with' indicates putting letters inside.
'that's wild' indicates an anagram.
'nature' is an anagram of 'turean'.
'a' going into 'turean' is 'TAUREAN'.
(Other definitions for taurean that I've seen before include "May Day baby, say?" , "One born under the sign of the bull" , "One born in April/May" , "person who might be considered bullish?" , "bovine" .)