Osteomancer Adept

If Dryad Arbor (the only card that's both a creature and a land) is in your graveyard, you can't play it this way. Dryad Arbor can't be cast as a spell.

You must still follow timing restrictions and permissions for creature spells you cast with the permission granted by Osteomancer Adept's last ability. Normally, you'll be able to cast them only during your main phase while the stack is empty.

Once you announce that you're casting a spell or activating an ability, players can't take actions until you've finished doing so. Notably, opponents can't try to remove cards from your graveyard or Foods you control to stop you from foraging.

Finality counters don't stop permanents from going to zones other than the graveyard from the battlefield. For example, if a permanent with a finality counter on it would be put into its owner's hand from the battlefield, it does so normally.

Finality counters work on any permanent, not only creatures. If a permanent with a finality counter on it would be put into a graveyard from the battlefield, exile it instead.

If you don't have enough cards in your graveyard or a Food on the battlefield, you can't choose to forage.

Multiple finality counters on a single permanent are redundant.