を生やした

grew (a beard or mustache)

→ を
phrase Rare #40,950
grew (a beard or mustache) Used with facial hair such as a beard or mustache. It can also mean that someone had grown or was wearing facial hair, depending on context.
JA: 彼は最近、口ひげを生やした。
EN: He recently grew a mustache.

それに口ひげを生やしたかわいい男の子乗ってる

There's also a cute boy with a mustache riding on it.

— ウィキッド ふたりの魔女 (2024)

彼は休暇中あごひげを生やした

He grew a beard while he was on vacation.

トム口ひげを生やした

Tom grew a mustache.