28 cards where (the card types include “creature” and the card types include “elemental”) and the colors ≤ GRU and the set is “m20”

Air Elemental (Core Set 2020 #44)
Boreal Elemental (Core Set 2020 #49)
Cavalier of Flame (Core Set 2020 #125)
Cavalier of Gales (Core Set 2020 #52)
Cavalier of Thorns (Core Set 2020 #167)
Chandra's Embercat (Core Set 2020 #129)
Chandra's Spitfire (Core Set 2020 #132)
Cloudkin Seer (Core Set 2020 #54)
Creeping Trailblazer (Core Set 2020 #207)
Fire Elemental (Core Set 2020 #138)
Frost Lynx (Core Set 2020 #62)
Healer of the Glade (Core Set 2020 #176)
Lavakin Brawler (Core Set 2020 #147)
Leafkin Druid (Core Set 2020 #178)
Lightning Stormkin (Core Set 2020 #213)
Omnath, Locus of the Roil (Core Set 2020 #216)
Overgrowth Elemental (Core Set 2020 #187)
Pyroclastic Elemental (Core Set 2020 #296)
Risen Reef (Core Set 2020 #217)
Scampering Scorcher (Core Set 2020 #158)
Scorch Spitter (Core Set 2020 #159)
Thicket Crasher (Core Set 2020 #196)
Thunderkin Awakener (Core Set 2020 #162)
Vorstclaw (Core Set 2020 #201)
Wakeroot Elemental (Core Set 2020 #202)
Waterkin Shaman (Core Set 2020 #288)
Wildfire Elemental (Core Set 2020 #297)
Yarok's Wavecrasher (Core Set 2020 #81)

In the blink of an eye, they strode from deep snow to the end of this search.