Conversation so far:
what was significant about Minotaur's birth?
After he ascended the throne of the island of Crete, Minos competed with his brothers to rule.
did he beat them and become ruler?
Minos prayed to Poseidon, the sea god, to send him a snow-white bull, as a sign of support (the Cretan Bull).
what was the competition?
CANNOTANSWER.

Question: what was his appearance?
Self-contained rewrite: What was Minos' appearance?