Yes, you can exile an indestructible permanent, be it a creature, artifact, enchantment, or land
In theory, this could become the cheapest Oblivion Ring out there, but it's locked to a hyper-specific strategy
Bring on the Night (Were/Wolves Matter) Cavern of Souls, Mayor of Avabruck, Waxing Moon, Full Moons Rise, Moonlight Hunt, Moonmist, Howlpack Resurgence, Ulrichs Kindred, Silverfur Partisan, Urzas Incubator, Mana Echoes, Deathrender, Quicksilver Amulet, Door of Destinies, Belbes Portal, Cryptic Gateway, Obelisk of Urd In addition to regular tribal inclusions like Urzas Incubator, Obelisk of Urd, and Door of Destinies I really like Belbes Portal and Cryptic Gateway here since they allow you to put Werewolves onto the battlefield without actually casting spells so you can potentially get the night trigger and flip them
Enchantment Color tag templates(None) Golgari Germination Whenever a nontoken creature you control dies, create a 1/1 green Saproling creature token
Even less desirable ones like Shire Terrace or Evolving Wilds can offer plenty of extra value
