this sounds more natural in the plural: https://books.google.com/ngrams/graph?content=a+lion+has+a+mane%2C+the+lion+has+a+mane%2C+lions+have+manes&year_start=1800&year_end=2019&corpus=26&smoothing=3&direct_url=t1%3B%2Cthe%20lion%20has%20a%20mane%3B%2Cc0%3B.t1%3B%2Clions%20have%20manes%3B%2Cc0