You should also be careful when trading cards with someone, especially if a trade seems too good to be true
Dystopia - Another cumulative upkeep enchantment, this time for black, that hoses green and white
Elvish Visionary was already a fantastic card, but now it flies, trades with anything, and has artifact synergies
Even paying for itself if you only have say four birds or lizards in play can help pay for itself the turn after it comes down
A triggered ability in Magic: The Gathering is an ability that automatically activates when a certain event or condition occurs
Back when the Magic 30th Anniversary set was released, for example, Earthbinds artwork was altered during its reprinting for similar reasons