"Monsters dwell in every heart. We only think civilization tames them."
—Euphemia, Nexus watcher

「怪物はあらゆる者の心の奥底に潜んでいる。それらを飼い慣らしているのが文明であると我々は考える。」――生息地の見張り、ユーフェミア

内にいる獣

パーマネント１つを対象とし、それを破壊する。それのコントローラーは緑の３/３のビースト・クリーチャー・トークンを１体戦場に出す。

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Beasties tend to be shy, kind to humans, and absolutely ruthless toward Valgavoth's monstrous spawn.

Duskmourn: House of Horror Commander

Bloomburrow Commander

Modern Horizons 3 Commander

The Lost Caverns of Ixalan Commander

"Do you recognize them? The Chagaskas. Your worst fears, my creativity."
—Zellin

Doctor Who

If the permanent is still a legal target but is not destroyed (perhaps because it regenerated or has indestructible), its controller still gets the Beast token.

If the target permanent is an illegal target by the time Beast Within tries to resolve, the spell won't resolve. No player creates a Beast token. If the target is legal but not destroyed (most likely because it has indestructible), its controller does create a Beast token.