The Necrobloom Serpent Whenever Cruel Celebrant or another

Whenever Cruel Celebrant or another creature or planeswalker you control dies

Whenever you cycle or discard a card

Lair Scavenger

it deals 2 damage to any target" and "{T}: Add one mana of any color

then sacrifice it unless you pay its upkeep cost for each age counter on it

The Necrobloom Serpent Whenever Cruel Celebrant or anotherLandfall Whenever a land enters the battlefield under your control, create a 0 1 green Plant creature token. If you control seven or more lands with different names, create a 2 2 black Zombie creature token instead. Land cards in your graveyard have dredge 2. (You may return a land card from your graveyard to your hand and mill two cards instead of drawing a card.)