18 cards where the cards aren’t reprints and the mana cost is greater than or equal to {1}{R}{G}{G}

Omnath, Locus of Rage (Battle for Zendikar #217)
Kogla and Yidaro (March of the Machine #244)
Dragonlair Spider (Planechase 2012 #87)
Borborygmos Enraged (Gatecrash #147)
Rulik Mons, Warren Chief (Dominaria United #217)
Spellbreaker Behemoth (Alara Reborn #60)
Godsire (Shards of Alara #170)
Ravager Wurm (Ravnica Allegiance #200)
Borborygmos (Guildpact #103)
Revel of the Fallen God (Journey into Nyx #155)
Vaevictis Asmadi (Legends #269)
Palladia-Mors (Legends #247)
Rumbling Slum (Guildpact #126)
Jerrard of the Closed Fist (Legends #235)
Livonya Silone (Legends #242)
Viashivan Dragon (Visions #140)
"Ach! Hans, Run!" (Unhinged #116)
A-Rulik Mons, Warren Chief (Dominaria United #A-217)

This search is finished. Now the real work can begin.