It could have been dropped there not from the stack at all, but, say, discarded from hand or put from the library
(You may cast this card from your graveyard for its escape cost.) Legendary Creature - Elder Giant Discard (CTRL to add secondary) Draw Broodbirth Viper Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control
Be conscious of how removal can affect your attacks
Academy Rector Aphetto Vulture Blightsteel Colossus Charforger Chimney Imp Clone Shell Darksteel Colossus Dread Dreadhound Elvish Soultiller Emrakul, the Aeons Torn Gamekeeper Ghostly Castigator Golgari Thug Gravebane Zombie Grazing Kelpie Guile Hoarding Dragon Hostility Iname as One Kozilek, Butcher of Truth Lost Auramancers Nissa's Chosen Progenitus Protean Hulk Purity Ringskipper Rooting Kavu Rootrunner Sadistic Augermage Seedguide Ash Seer of Stolen Sight Serra Avatar Skirk Drill Sergeant Solemn Simulacrum Syr Konrad, the Grim Syr Konrad, the Grim The Lady of Otaria Ulamog, the Infinite Gyre Veteran Explorer Vigor Vigor Viridian Emissary Whirlpool Drake Wirewood Herald Worldspine Wurm Yavimaya Elder
In case you've heard the term but don't know the cards, here's a rundown of the original Power Nine: Honorable Mention: Library of Alexandria, arguably Magic's most powerful land, rounds out most people's list of the Power Ten