30 cards where the rarity is equal to common and the text includes “proliferate”

Adaptive Sporesinger (Phyrexia: All Will Be One #157)
Blightbelly Rat (Phyrexia: All Will Be One #85)
Bloom Hulk (War of the Spark #154)
Carnival Elephant Meteor (Unfinity Sticker Sheets #7)
Carnivorous Canopy (Phyrexia: All Will Be One #162)
Contagious Vorrac (Phyrexia: All Will Be One #164)
Contentious Plan (War of the Spark #46)
Copper Longlegs (Phyrexia: All Will Be One #165)
Courage in Crisis (Commander Masters #278)
Experimental Augury (Phyrexia: All Will Be One #49)
Fuel for the Cause (Mirrodin Besieged #25)
Gitaxian Anatomist (Phyrexia: All Will Be One #52)
Grim Affliction (Modern Masters 2015 #84)
Guildpact Informant (War of the Spark #271)
Gulping Scraptrap (Phyrexia: All Will Be One #96)
Kiora's Dambreaker (Ravnica Remastered #48)
Martyr for the Cause (War of the Spark #23)
Mesmerizing Dose (Phyrexia: All Will Be One #62)
Pollenbright Druid (Commander Masters #312)
Smell Fear (Modern Horizons 2 #173)
Spread the Sickness (Duel Decks: Mirrodin Pure vs. New Phyrexia #79)
Steady Progress (Modern Masters 2015 #58)
Thirsting Roots (Phyrexia: All Will Be One #185)
Thrummingbird (Modern Masters 2015 #65)
Unbounded Potential (Commander Masters #67)
Urban Daggertooth (Modern Horizons 2 #181)
Vivisurgeon's Insight (Phyrexia: All Will Be One #77)
Volt Charge (Phyrexia: All Will Be One #155)
Wanderer's Strike (Commander Masters #69)
Whisper of the Dross (Phyrexia: All Will Be One #117)

Their mind whirled with grand plans, never thinking of what might happen if they got to the end of the list.