It's A Bit Of A Puzzle Given how uncommon it is for Charizard to be knocked off its number one pedestal, it's no doubt surprising that Greninja ex was the card to do so

Julius Jumblemorph Ixalan Vona, Butcher of Magan , Tishana, Voice of Thunder , Admiral Beckett Brass , Gishath, Suns Avatar Commander 2017 Nazahn, Revered Bladesmith , Inalla, Archmage Ritualist , Mirri, Weatherlight Duelist , O-Kagachi, Vengeful Kami , Mairsil, the Pretender , Taigam, Ojutai Master Razaketh, the Foulblooded , Zur, the Enchanter (Mummys Curse), Djeru, With Eyes Open , The Locust God , Karona, False God (All the Deserts), Nicol Bolas , Neheb, the Eternal Amonkhet Oketra the True , Temmet, Vizier of Naktamun , Atogatog (Cartouches & Trials), Hapatra, Vizier of Poisons , Samut, Voice of Dissent , Rhonas the Indomitable , Hazoret the Fervent Kaladesh Block Yahenni, Undying Partisan , Nicol Bolas , Child of Alara (5 Color Energy), Rishkar, Peema Renegade , Kari Zev, Skyship Raider , Sram, Senior Edificer Commander 2016 Breya, Etherium Shaper , Atraxa, Praetors Voice , Tymna the Weaver // Ravos, Soultender Other Commander Decks Momir Vig, Simic Visionary (no green creatures), Kytheon, Hero of Akros (Tribal Gideon) Commander Strategy

Creature - Elf Druid Tempt with Discovery Tempting offer Search your library for a land card and put it onto the battlefield
This Jumbo Cactuar is one of them