All right for a Greek character to have an animal (5)
I believe the answer is:
Here is my best explanation:
'an animal' is the definition.
(I've seen this before)
'all right for a greek character' is the wordplay.
'all right' becomes 'ok' ('ok' can be a synonym of 'all right').
'for' is a charade indicator (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 "African animal like giraffe with shorter neck and striped body", "Horned ruminant", "Giraffe family mammal", "Relative of giraffe", "rainforest ruminant", "Central African resident", "Central Afr. ruminant", "Native of Central Africa", "African leaves fancier" and "Animal, a sort of zebra/giraffe cross".)