Krenko doesn't need a complicated plan. Make Goblins. Make more Goblins. Then make an absolutely unreasonable number of Goblins. Swarm the board, turn sideways, and let the little guys do what they do best.
Commander
1x Krenko, Mob Boss
Creatures
1x Battle-Scarred Goblin
1x Breeches, Eager Pillager
1x Changeling Berserker
1x Cinder Seer
1x Fanatical Firebrand
1x Frenzied Goblin
1x Goblin Gang Leader
1x Goblin Matron
1x Goblin Medics
1x Goblin Shortcutter
1x Goblin Tomb Raider
1x Goblin Warchief
1x Grenzo, Havoc Raiser
1x Guttersnipe
1x Impulsive Pilferer
1x Krenko, Baron of Tin Street
1x Legion Warboss
1x Pyrewild Shaman
1x Redcap Heelslasher
1x Redcap Thief
1x Sardian Avenger
1x Searglider Goblin
1x Spikeshot Goblin
1x Squee, Dubious Monarch
1x Squee, Goblin Nabob
1x Storm-Kiln Artist
1x Tin Street Dodger
1x Treasure Nabber
1x Twinshot Sniper
1x Zada, Hedron Grinder
Instants
1x Abrade
1x Ambush
1x Falter
1x Goblin Surprise
1x Goblin Wizardry
1x Molten Blast
1x Tarfire
1x Unleash Shell
1x You Come to the Gnoll Camp
Sorceries
1x Act of Treason
1x Concussive Bolt
1x Dragon Fodder
1x Empty the Warrens
1x Gamble
1x Goblin Negotiation
1x Goblin War Party
1x Krenko's Command
1x Mogg Infestation
1x Pillar of Flame
1x Renegade Tactics
Artifacts
1x Bonesplitter
1x Diamond Pick-Axe
1x Dowsing Device // Geode Grotto
1x Fleetfeather Sandals
1x Icon of Ancestry
1x Lightning Greaves
1x Matzalantli, the Great Door // The Core
1x Sol Ring
1x Staff of the Flame Magus
1x Tiran's Soulcleaver
Enchantments
1x Etali's Favor
1x Goblin War Drums
1x Impact Tremors
Lands
33x Mountain
1x Myriad Landscape
1x Opal Palace
1x Path of Ancestry