Play Glacial Chasm either from your hand or from your graveyard.
When Glacial Chasm enters the battlefield, its second ability triggers, causing you to sacrifice another land you control.
Play any land from your graveyard.
At the beginning of your next upkeep, Glacial Chasm's cumulative upkeep ability triggers, allowing you to choose not to pay the cost and sacrifice it instead.
Repeat.

Prevent all damage that would be dealt to you

Lock

Glacial Chasm

Ramunap Excavator

Case of the Locked Hothouse

Activate Phyrexian Altar by sacrificing the nontoken creature, adding one mana of any color.
When the creature dies, Mortuary triggers, putting the creature from your graveyard onto the top of your library.
Cast the creature by paying its mana cost.
Repeat.

Infinite creature LTB

Infinite creature ETB

Infinite creature sacrifice triggers

Infinite death triggers

Infinite storm count

Mortuary

Phyrexian Altar

Activate Ashnod's Altar by sacrificing the creature that can be cast using {C}{C}, adding {C}{C}.
When the creature dies, Mortuary triggers, putting the creature from your graveyard onto the top of your library.
Cast the creature from the top of your library by paying its mana cost.
Repeat.

Infinite colorless mana

Creature Castable for {C}{C}

Ashnod's Altar

Activate the Sliver that can be cast using {B}{B} by sacrificing it, adding {B}{B}.
The Sliver is put onto the top of your library instead of into your graveyard due to the replacement effect given to it by Pulmonic Sliver.
Cast the Sliver from the top of your library by paying its mana cost.
Repeat.

Sliver Castable for {B}{B}

Pulmonic Sliver

Basal Sliver

Activate Hammerhead by sacrificing the nontoken creature.
When the creature dies, Mortuary and Pitiless Plunderer trigger.
Resolve the Mortuary trigger, putting the creature from your graveyard onto the top of your library.
Resolve the Pitiless Plunderer trigger, creating a Treasure token.
Resolve the Hammerhead ability.
Activate the Treasure by tapping and sacrificing it, adding one mana of any color.
Cast the creature from the top of your library by paying its mana cost
Repeat.

Infinite +1/+1 counters on a creature

Infinite artifact ETB

Infinite artifact LTB

Infinite artifact sacrifice triggers

Pitiless Plunderer

Hammerhead, Maggia Boss

Activate Phyrexian Altar by sacrificing Golgari Thug, adding {B}.
When Golgari Thug dies, it triggers, returning it from your graveyard to the top of your library.
Wan Shi Tong's second ability triggers, creating two 1/1 Spirit creature tokens.
Activate Phyrexian Altar by sacrificing a Spirit, adding {1}.
Cast Golgari Thug from the top of your library by paying {1}{B}.
Repeat.

Infinite colored mana

Infinite creature tokens

Wan Shi Tong, All-Knowing

Golgari Thug

Cast Charismatic Conqueror from the top of your library by paying {1}{W}.
Charismatic Conqueror's demonstrate ability triggers, causing you and an opponent to copy it.
Resolve the opponent's copy of Charismatic Conqueror, and then resolve your copy of Charismatic Conqueror.
When your Charismatic Conqueror token enters the battlefield,  the opponent's Charismatic Conqueror triggers, causing you to tap your Charismatic Conqueror token.
Resolve the original Charismatic Conqueror spell.
When the nontoken Charismatic Conqueror enters the battlefield, the opponent's Charismatic Conqueror triggers, causing you to not tap the nontoken Charismatic Conqueror, and causing the opponent to create a 1/1 Vampire creature token.
When the opponent's Vampire token enters the battlefield, both Charismatic Conquerors you control trigger, causing you to create at least one 1/1 Vampire creature token.
When your Vampire token enters the battlefield, the opponent's Charismatic Conqueror triggers, causing you to not tap the Vampire token, and causing the opponent to create a 1/1 Vampire creature token.
Repeat from step 7.

Infinite creature ETB for target opponent

Infinite creature tokens for target opponent

Charismatic Conqueror

The Twelfth Doctor

Combos with "Case of the Locked Hothouse"