gnu
Gnu.
gnu
A three letter African antelope is the "gnu", which ends in a "u" not a "you". The more common name for the gnu is the wildebeeste, but that won't fit into your crossword puzzle.
Gnu is a three letter word for an African antelope
gnu
Kudu :striped African antelope
Some three letter words beginning with D are:diddogdoediedendindabduodotdigdrydye
que
There are none.
and Ant
ope
Hue