pokemon trading card game: hidden fates elite trainer box TCG – True Believers Gaming and Collectibles which featured 94 shiny Pokémon including Umbreon Pokemon: Hidden Fates Elite Trainer

It will remain there for the rest of the game

You can tap this with no mana to shoot an attacking dork for 1 damage but only at the end of the combat step, so you'll take it first

You can technically do this without spending any money/gold/gems and just open packs you get for free while playing the game

Certainly not quite what youre after, but just to get this out of the way: the Dark Arbok card from Team Rocket has an erroneous 1999-23000 Wizards: 465640 77.7 KB This is similar to the Japanese Ancient Mew error which has Nintedo instead of Nintendo

Commander 2015 actually has a few other cards like this, that extend known mechanics to include additional players or all players