Deer - it gets one foot twisted (6)
I believe the answer is:
wapiti
'deer' is the definition.
(wapiti is a kind of deer)
'it gets one foot twisted' is the wordplay.
'gets' means one lot of letters go next to another.
'one' becomes 'i' (Roman numeral).
'foot' becomes 'paw' (paw is a kind of foot).
'twisted' is a reversal indicator.
'it'+'i'+'paw'='itipaw'
'itipaw' reversed gives 'WAPITI'.
(Other definitions for wapiti that I've seen before include "Red deer - I paw it (anag)" , "Animal" , "Large N. Am. red deer" , "North American native" , "I paw it (anag) - large North American deer" .)