Frilled Cave-Wurm

Descend 4 — Frilled Cave-Wurm gets +2/+0 as long as there are four or more permanent cards in your graveyard.

Neera, Wild Mage

Whenever you cast a spell, you may put it on the bottom of its owner's library. If you do, reveal cards from the top of your library until you reveal a nonland card. You may cast that card without paying its mana cost. Then put all revealed cards not cast this way on the bottom of your library in a random order. This ability triggers only once each turn.

Hollowsage

Whenever Hollowsage becomes untapped, you may have target player discard a card.

Ursine Fylgja

Ursine Fylgja enters the battlefield with four healing counters on it.
Remove a healing counter from Ursine Fylgja: Prevent the next 1 damage that would be dealt to Ursine Fylgja this turn.
{2}{W}: Put a healing counter on Ursine Fylgja.