Cast Shrieking Drake by paying {U}.
Ms. Bumbleflower triggers, causing an opponent to draw a card who cannot pay for Smothering Tithe's trigger, and putting a +1/+1 counter on a creature.
Smothering Tithe triggers, creating a Treasure token, as the opponent who drew a card cannot pay for its trigger.
When Shrieking Drake enters, it triggers, returning it from the battlefield to your hand.
Activate the Treasure by tapping and sacrificing it, adding {U}.
Repeat.

Near-infinite +1/+1 counters

Near-infinite creature ETB

Near-infinite storm count

Near-infinite creature LTB

Infinite card draw for opponents

Infinite draw triggers for each opponent

Ms. Bumbleflower

Shrieking Drake

Smothering Tithe

Cast Shrieking Drake by paying {U}.
Ms. Bumbleflower triggers, causing an opponent to draw a card and putting a +1/+1 counter on Crystalline Crawler.
When Shrieking Drake enters, it triggers, returning it from the battlefield to your hand.
Activate Crystalline Crawler by removing a +1/+1 counter from it, adding {U}.
Repeat.

Crystalline Crawler

Cast the self-sacrificing artifact in your hand by paying {0}.
Ms. Bumbleflower triggers, causing an opponent to draw a card, and then putting a +1/+1 counter on Evolution Witness.
Evolution Witness triggers, returning the self-sacrificing artifact from your graveyard to your hand.
Activate the self-sacrificing artifact cast in step 1 by sacrificing it, and paying other costs if necessary.
Repeat.

Infinite storm count

Infinite card draw at the beginning of the next upkeep

Infinite draw triggers for any number of opponents

Infinite card draw for any number of opponents

Infinite draw triggers at the beginning of the next upkeep

Infinite +1/+1 counters on a creature

Evolution Witness

Mishra's Bauble

Urza's Bauble

Cast Shrieking Drake by paying {U}.
Ms. Bumbleflower triggers, causing an opponent to draw a card and putting a +1/+1 counter on Berta.
Berta triggers, adding {U}.
When Shrieking Drake enters, it triggers, returning it from the battlefield to your hand.
Repeat.

Near-infinite +1/+1 counters on a creature

Berta, Wise Extrapolator

Combos with "Ms. Bumbleflower"