Cast Shrieking Drake by paying {U}.
Primeval Bounty triggers, creating a creature token.
When Shrieking Drake enters the battlefield, it triggers, returning itself from the battlefield to your hand.
Activate Phyrexian Altar by sacrificing the creature token, adding {U}.
Repeat.

Infinite death triggers

Infinite creature ETB

Infinite creature LTB

Infinite creature sacrifice triggers

Infinite storm count

Shrieking Drake

Phyrexian Altar

Primeval Bounty

Activate Altar of Dementia by sacrificing Hogaak.
When Hogaak dies, The Skullspore Nexus triggers, creating a creature token.
Resolve the Altar of Dementia ability, causing you to mill eight cards.
Cast Hogaak from your graveyard by exiling five cards from your graveyard and tapping two black and/or green creatures you control.
Primeval Bounty triggers, creating a 3/3 Beast creature token.
Repeat.

Near-infinite creature ETB

Near-infinite storm count

Near-infinite creature LTB

Exile your library

Near-infinite mill

Near-infinite death triggers

Near-infinite creature sacrifice triggers

Near-infinite tapped creature tokens

Hogaak, Arisen Necropolis

Altar of Dementia

The Skullspore Nexus

Cast Whitemane Lion by paying {1}{W}.
Primeval Bounty's first ability triggers, creating a 3/3 Beast creature token.
When Whitemane Lion enters the battlefield, it and Arahbo trigger.
Resolve the Whitemane Lion trigger, returning it from the battlefield to your hand.
Resolve the Arahbo trigger, creating a 1/1 Cat creature token.
Activate Phyrexian Altar twice by sacrificing the Cat and Beast, adding {1}{W}.
Repeat.

Arahbo, the First Fang

Whitemane Lion

Cast Realm-Scorcher Hellkite by paying {4}{R}{R} and sacrificing an additional artifact, enchantment or token.
Primeval Bounty's first ability triggers, creating a 3/3 Beast creature token.
When Realm-Scorcher Hellkite enters the battlefield, it triggers, adding {2}{R}{R}.
Activate Ashnod's Altar by sacrificing Realm-Scorcher Hellkite, adding {C}{C}.
When Realm-Scorcher Hellkite dies, Enduring Renewal triggers, returning it to your hand from your graveyard.
Repeat.

Infinite colorless mana

Realm-Scorcher Hellkite

Enduring Renewal

Ashnod's Altar

Activate Grimgrin's ability from Song of Freyalise by tapping Grimgrin, adding one mana.
Activate Grimgrin by sacrificing the creature castable for one mana, untapping Grimgrin and putting a +1/+1 counter on it.
Activate Grimgrin's ability from Song of Freyalise by tapping Grimgrin, adding one mana.
Activate Havengul Lich by paying {1}, allowing you to cast the creature castable for one mana from your graveyard this turn.
Cast that creature spell from your graveyard by paying it mana cost.
When you cast that creature or when it enters, Primeval Bounty triggers, creating a creature token.
Activate Grimgrin by sacrificing the creature token, untapping Grimgrin and putting a +1/+1 counter on it.
Repeat.

Infinite +1/+1 counters on a creature

Creature Castable for One Colored Mana

Havengul Lich

Grimgrin, Corpse-Born

Song of Freyalise

Cast Ebondeath from your graveyard by paying {B}{B} due to Green Goblin.
Primeval Bounty triggers, creating a creature token.
Activate Phyrexian Altar by sacrificing the creature token and Ebondeath, adding {B}{B}.
Repeat.

Norman Osborn // Green Goblin

Ebondeath, Dracolich

Combos with "Primeval Bounty"