Trap managed to catch one animal (5)
I believe the answer is:
tapir
'animal' is the definition.
(tapir is a type of animal)
'trap managed to catch one' is the wordplay.
'managed' indicates anagramming the letters.
'to catch' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'trap' anagrammed gives 'tapr'.
'tapr' enclosing 'i' is 'TAPIR'.
(Other definitions for tapir that I've seen before include "Tropical hoofed mammal with a flexible proboscis" , "nocturnal beast" , "Hoofed mammal; I trap (anag.)" , "Nocturnal hoofed animal" , "Animal with elongated snout" .)