These are all the infinite combos I'm aware of using the cards that are in the deck, not including the cards in the Maybeboard. I've put every variant to show how much potential is in the deck so it may look repetitive.
GAME WINNING COMBOS - INFINITE TOKENS/ATTACKS: Have a creature besides Krenko, enchant it with Breath of Fury, activate Krenko, attack directly with enchanted creature, sacrifice enchanted creature, enchant another creature besides Krenko with Breath of Fury, untap all creatures, equip haste equipment to enchanted creature, repeat from "activate Krenko"
Krenko, Mob Boss + Breath of Fury + Battlemage's Bracers
Krenko, Mob Boss + Breath of Fury + Fervor
Krenko, Mob Boss + Breath of Fury + Goblin Chieftain
Krenko, Mob Boss + Breath of Fury + Goblin Warchief
Krenko, Mob Boss + Breath of Fury + Hammer of Purphoros
Krenko, Mob Boss + Breath of Fury + Lightning Greaves
Krenko, Mob Boss + Breath of Fury + Mass Hysteria
GAME WINNING COMBOS - INFINITE TOKENS/DAMAGE/ATTACKS: Enchant token with Breath of Fury, tap Krenko, tap Hobgoblin Bandit Lord, attack directly with enchanted token, sacrifice enchanted token, enchant another token with Breath of Fury, untap all creatures, equip haste equipment to enchanted token or activate creature haste ability, repeat from "tap Krenko"
Krenko, Mob Boss + Breath of Fury + Hobgoblin Bandit Lord + Battlemage's Bracers
Krenko, Mob Boss + Breath of Fury + Hobgoblin Bandit Lord + Fervor
Krenko, Mob Boss + Breath of Fury + Hobgoblin Bandit Lord + Goblin Chieftain
Krenko, Mob Boss + Breath of Fury + Hobgoblin Bandit Lord + Goblin Warchief
Krenko, Mob Boss + Breath of Fury + Hobgoblin Bandit Lord + Hammer of Purphoros
Krenko, Mob Boss + Breath of Fury + Hobgoblin Bandit Lord + Lightning Greaves
Krenko, Mob Boss + Breath of Fury + Hobgoblin Bandit Lord + Mass Hysteria
Krenko, Mob Boss + Breath of Fury + Hobgoblin Bandit Lord + Swiftfoot Boots
INFINITE TOKENS/MANA: Tap Krenko, return Krenko to hand, sacrifice tokens for mana, play Krenko, equip haste equipment or activate creature haste ability, repeat
Krenko, Mob Boss + Cloudstone Curio + Phyrexian Altar + Battlemage's Bracers
Krenko, Mob Boss + Cloudstone Curio + Phyrexian Altar + Fervor
Krenko, Mob Boss + Cloudstone Curio + Phyrexian Altar + Goblin Chieftain
Krenko, Mob Boss + Cloudstone Curio + Phyrexian Altar + Goblin Warchief
Krenko, Mob Boss + Cloudstone Curio + Phyrexian Altar + Hammer of Purphoros
Krenko, Mob Boss + Cloudstone Curio + Phyrexian Altar + Lightning Greaves
Krenko, Mob Boss + Cloudstone Curio + Phyrexian Altar + Mass Hysteria
Krenko, Mob Boss + Cloudstone Curio + Phyrexian Altar + Swiftfoot Boots
Krenko, Mob Boss + Cloudstone Curio + Skirk Prospector + Battlemage's Bracers
Krenko, Mob Boss + Cloudstone Curio + Skirk Prospector + Fervor
Krenko, Mob Boss + Cloudstone Curio + Skirk Prospector + Goblin Chieftain
Krenko, Mob Boss + Cloudstone Curio + Skirk Prospector + Goblin Warchief
Krenko, Mob Boss + Cloudstone Curio + Skirk Prospector + Hammer of Purphoros
Krenko, Mob Boss + Cloudstone Curio + Skirk Prospector + Lightning Greaves
Krenko, Mob Boss + Cloudstone Curio + Skirk Prospector + Mass Hysteria
Krenko, Mob Boss + Cloudstone Curio + Skirk Prospector + Swiftfoot Boots
GAME WINNING COMBOS - INFINITE TOKENS/DAMAGE/MANA: Tap Krenko, return Krenko to hand, sacrifice tokens for mana, play Krenko, equip haste equipment or activate creature haste ability, repeat until satisfied, tap Hobgoblin Bandit Lord, tap Krenko, return Krenko and Hobgoblin Bandit Lord to hand, sacrifice tokens for mana, play Krenko and Hobgoblin Bandit Lord, equip haste equipment to hobgoblin Bandit Lord or activate creature haste ability, repeat from "tap Hobgoblin Bandit Lord" and move haste equipment from Hobgoblin Bandit Lord to Krenko after ability activation if using equipment for haste
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Phyrexian Altar + Battlemage's Bracers
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Phyrexian Altar + Fervor
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Phyrexian Altar + Goblin Chieftain
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Phyrexian Altar + Goblin Warchief
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Phyrexian Altar + Hammer of Purphoros
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Phyrexian Altar + Lightning Greaves
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Phyrexian Altar + Mass Hysteria
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Phyrexian Altar + Swiftfoot Boots
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Skirk Prospector + Battlemage's Bracers
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Skirk Prospector + Fervor
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Skirk Prospector + Goblin Chieftain
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Skirk Prospector + Goblin Warchief
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Skirk Prospector + Hammer of Purphoros
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Skirk Prospector + Lightning Greaves
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Skirk Prospector + Mass Hysteria
Krenko, Mob Boss + Cloudstone Curio + Hobgoblin Bandit Lord + Skirk Prospector + Swiftfoot Boots
INFINITE TOKENS/MANA: Tap Krenko, sacrifice tokens for mana (unless using Mana Echoes, just gain mana from it's effect), activate Staff of Domination 4 cost ability on Krenko, activate Staff of Domination 1 cost ability, repeat
Krenko, Mob Boss + Staff of Domination + Ashnod's Altar
Krenko, Mob Boss + Staff of Domination + Mana Echoes
Krenko, Mob Boss + Staff of Domination + Phyrexian Altar
Krenko, Mob Boss + Staff of Domination + Skirk Prospector
GAME WINNING COMBOS - INFINITE TOKENS/DAMAGE: Tap Krenko, sacrifice tokens for mana (unless using Mana Echoes, just gain mana from it's effect), activate Staff of Domination 4 cost ability on Krenko, activate Staff of Domination 1 cost ability, repeat until satisfied, tap Hobgoblin Bandit Lord, activate Staff of Domination 4 cost ability on Hobgoblin Bandit Lord, activate Staff of Domination 1 cost ability, repeat until game win
Krenko, Mob Boss + Staff of Domination + Hobgoblin Bandit Lord + Ashnod's Altar
Krenko, Mob Boss + Staff of Domination + Hobgoblin Bandit Lord + Mana Echoes
Krenko, Mob Boss + Staff of Domination + Hobgoblin Bandit Lord + Phyrexian Altar
Krenko, Mob Boss + Staff of Domination + Hobgoblin Bandit Lord + Skirk Prospector
INFINITE TOKENS/MANA: Equip Sword of the Paruns to Krenko, tap Krenko, sacrifice tokens for mana (unless using Mana Echoes, just gain mana from it's effect), activate Sword of the Paruns untap ability, repeat from "tap Krenko"
Krenko, Mob Boss + Sword of the Paruns + Ashnod's Altar
Krenko, Mob Boss + Sword of the Paruns + Mana Echoes
Krenko, Mob Boss + Sword of the Paruns + Phyrexian Altar
Krenko, Mob Boss + Sword of the Paruns + Skirk Prospector
INFINITE TOKENS: Equip Thornbite Staff to Krenko, tap Krenko, sacrifice token, untap Krenko, repeat from "tap Krenko"
Krenko, Mob Boss + Thornbite Staff + Ashnod's Altar
Krenko, Mob Boss + Thornbite Staff + Goblin Chirurgeon
Krenko, Mob Boss + Thornbite Staff + Phyrexian Altar
Krenko, Mob Boss + Thornbite Staff + Skirk Prospector
GAME WINNING COMBO - INFINITE TOKENS/MILL: Equip Thornbite Staff to Krenko, tap Krenko, sacrifice token to mill opponent 1 card, untap Krenko, repeat from "tap Krenko"
Krenko, Mob Boss + Thornbite Staff + Altar of Dementia
GAME WINNING COMBO - INFINITE TOKENS/DAMAGE: Equip Thornbite Staff to Krenko, tap Krenko, sacrifice token to deal 1 damage to any target, untap Krenko, repeat from "tap Krenko"
Krenko, Mob Boss + Thornbite Staff + Goblin Bombardment
GAME WINNING COMBOS - INFINITE TOKENS THEN ATTACK: Equip Thornbite Staff to Krenko, tap Krenko, sacrifice token, untap Krenko, repeat from "tap Krenko" until satisfied, activate creature haste ability, attack with all tokens
Krenko, Mob Boss + Thornbite Staff + Altar of Dementia + Fervor
Krenko, Mob Boss + Thornbite Staff + Altar of Dementia + Goblin Chieftain
Krenko, Mob Boss + Thornbite Staff + Altar of Dementia + Goblin Warchief
Krenko, Mob Boss + Thornbite Staff + Altar of Dementia + Hammer of Purphoros
Krenko, Mob Boss + Thornbite Staff + Altar of Dementia + Mass Hysteria
Krenko, Mob Boss + Thornbite Staff + Ashnod's Altar + Fervor
Krenko, Mob Boss + Thornbite Staff + Ashnod's Altar + Goblin Chieftain
Krenko, Mob Boss + Thornbite Staff + Ashnod's Altar + Goblin Warchief
Krenko, Mob Boss + Thornbite Staff + Ashnod's Altar + Hammer of Purphoros
Krenko, Mob Boss + Thornbite Staff + Ashnod's Altar + Mass Hysteria
Krenko, Mob Boss + Thornbite Staff + Goblin Bombardment + Fervor
Krenko, Mob Boss + Thornbite Staff + Goblin Bombardment + Goblin Chieftain
Krenko, Mob Boss + Thornbite Staff + Goblin Bombardment + Goblin Warchief
Krenko, Mob Boss + Thornbite Staff + Goblin Bombardment + Hammer of Purphoros
Krenko, Mob Boss + Thornbite Staff + Goblin Bombardment + Mass Hysteria
Krenko, Mob Boss + Thornbite Staff + Goblin Chirurgeon + Fervor
Krenko, Mob Boss + Thornbite Staff + Goblin Chirurgeon + Goblin Chieftain
Krenko, Mob Boss + Thornbite Staff + Goblin Chirurgeon + Goblin Warchief
Krenko, Mob Boss + Thornbite Staff + Goblin Chirurgeon + Hammer of Purphoros
Krenko, Mob Boss + Thornbite Staff + Goblin Chirurgeon + Mass Hysteria
Krenko, Mob Boss + Thornbite Staff + Phyrexian Altar + Fervor
Krenko, Mob Boss + Thornbite Staff + Phyrexian Altar + Goblin Chieftain
Krenko, Mob Boss + Thornbite Staff + Phyrexian Altar + Goblin Warchief
Krenko, Mob Boss + Thornbite Staff + Phyrexian Altar + Hammer of Purphoros
Krenko, Mob Boss + Thornbite Staff + Phyrexian Altar + Mass Hysteria
Krenko, Mob Boss + Thornbite Staff + Skirk Prospector + Fervor
Krenko, Mob Boss + Thornbite Staff + Skirk Prospector + Goblin Chieftain
Krenko, Mob Boss + Thornbite Staff + Skirk Prospector + Goblin Warchief
Krenko, Mob Boss + Thornbite Staff + Skirk Prospector + Hammer of Purphoros
Krenko, Mob Boss + Thornbite Staff + Skirk Prospector + Mass Hysteria
INFINITE TOKENS/MANA: Equip Umbral Mantle to Krenko, tap Krenko, sacrifice tokens for mana (unless using Mana Echoes, just gain mana from it's effect), activate Umbral Mantle ability, repeat from "tap Krenko"
Krenko, Mob Boss + Umbral Mantle + Ashnod's Altar
Krenko, Mob Boss + Umbral Mantle + Mana Echoes
Krenko, Mob Boss + Umbral Mantle + Phyrexian Altar
Krenko, Mob Boss + Umbral Mantle + Skirk Prospector
INFINITE TOKENS/MANA: Play Lightning Crafter (Champion another creature), play Kiki-Jiki, activate Kiki-Jiki targeting Lightning Crafter, champion Kiki-Jiki with Lightning Crafter copy, sacrifice Lightning Crafter copy, return Kiki-Jiki to field untapped, repeat from Kiki-Jiki activation
Kiki-Jiki, Mirror Breaker + Lightning Crafter + Altar of Dementia
Kiki-Jiki, Mirror Breaker + Lightning Crafter + Ashnod's Altar
Kiki-Jiki, Mirror Breaker + Lightning Crafter + Phyrexian Altar
Kiki-Jiki, Mirror Breaker + Lightning Crafter + Skirk Prospector
GAME WINNING COMBO - INFINITE TOKENS/DAMAGE: Play Lightning Crafter (Champion another creature), play Kiki-Jiki, activate Kiki-Jiki targeting Lightning Crafter, champion Kiki-Jiki with Lightning Crafter copy, sacrifice Lightning Crafter copy, return Kiki-Jiki to field untapped, repeat from Kiki-Jiki activation
Kiki-Jiki, Mirror Breaker + Lightning Crafter + Goblin Bombardment
INFINITE TOKENS: Play Lightning Crafter (Champion another creature), play Kiki-Jiki, activate Kiki-Jiki targeting Lightning Crafter, champion Kiki-Jiki with Lightning Crafter copy, sacrifice Lightning Crafter copy, return Kiki-Jiki to field untapped, repeat from Kiki-Jiki activation
Kiki-Jiki, Mirror Breaker + Lightning Crafter + Goblin Chirurgeon
INFINITE TOKENS/MANA:
Goblin Recruiter + Conspicuous Snoop + Torch Courier + Kiki-Jiki, Mirror Breaker + Ashnod's Altar
Goblin Recruiter + Conspicuous Snoop + Torch Courier + Kiki-Jiki, Mirror Breaker + Mana Echoes
Goblin Recruiter + Conspicuous Snoop + Torch Courier + Kiki-Jiki, Mirror Breaker + Phyrexian Altar
Goblin Recruiter + Conspicuous Snoop + Torch Courier + Kiki-Jiki, Mirror Breaker + Skirk Prospector