Alright for a Greek character to have an animal (5)
I believe the answer is:
Here is my best explanation:
'an animal' is the definition.
'alright for a greek character' is the wordplay.
'alright' becomes 'ok' ('OK' can be a synonym of 'alright').
'for' says to put letters next to each other.
'greek character' becomes 'pi' (letter from the Greek alphabet).
'to have' is the link.
(Other definitions for okapi that I've seen before include "Giraffe family member", "Ruminant mammal of Africa", "Wild animal", "Giraffe relative", "african", "Giraffe-like animal with stripes", "Horned ruminant", "Central African animal", "African animal related to the giraffe" and "One of the giraffe family".)