Pour mana into +1/+1 counters and watch mutated critters swell far beyond their size.
Sets your commander and theme, then adds about 25 cards that fit plus 20 lands. You fill in the rest.
The top 40 of 808 cards that fit

#7,889$0.35Jaime Jones

#15,584$0.95

#7,383$0.25James Bousema

#17,677$0.11

#1,582$34.03

#4,956$2.29Jason Kiantoro

#6,382$0.33

#7,463$5.99Heonhwa

#1,127$5.77Chris Rahn

#3,139$4.43John Tedrick

#14,962$0.33Howard Lyon

#7,125$8.75InHyuk Lee

#2,733$0.29Aaron J. Riley

#1,628$3.22Chase Stone

#2,515$6.16Kevin Sidharta

#6,580$0.13Jonas De Ro

#5,082$0.35Izzy

#2,845$25.57Gabor Szikszai

#5,237$1.90Raymond Swanland

#13,150$0.24James Ryman

#14,716$0.32Jeff Miracola

#8,934$0.32Andrey Kuzinskiy

#1,659$3.46Scott M. Fischer

#10,930$0.59Karl Kopinski

#7,532$0.38

#917$25.23Daniel Zrom

#17,979$0.05Clint Cearley

#10,317$0.38

#2,472$16.85

#19,653Chris Rallis

#22,436$0.09Tyler Jacobson

#1,591$16.75Lucas Graciano

#186$2.03Jim Nelson

#8,904$0.27Narendra Bintara Adi

#1,522$0.30Adam Paquette

#5,180$0.57Colin Boyer

#7,927$0.13Volkan Baǵa

#7,795$0.28Daarken

#7,762$15.05Billy Christian

#1,250$33.86Daarken