Additionally, Water Shuriken is a stackable ability, if the player has two Greninja on the field, they can distribute up to 40 damage per turn

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 (Five-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 Thada Adel, Acquisitor, The Ultimate Golgari Deck, Anafenza, the Foremost (shutting down shenanigans), Momir Vig, Simic Visionary (no green creatures), Kytheon, Hero of Akros (Tribal Gideon), Tasigur, the Golden Fang

I think this pairs best with partner commanders that either add card advantage (Tymna the Weaver) or access to colors with ramp (Jeska, Thrice Reborn or Reyhan, Last of the Abzan)
You don't choose a target for Atraxa's Skitterfang's last ability at the time it triggers
Decide What You Want to Collect Start by narrowing your focus: Are you collecting for nostalgia, gameplay, or investment
Im looking forward to slotting Bighorner Rancher right into my Grothama, All-Devouring deck because tapping this for ten green mana sounds amazing