Its one of the strongest card search abilities in the game now thanks to Ursulas Return, and well worth prioritizing if you end up playing Sapphire/Steel
An ideal example of this is the Shedinja card from the Vivid Voltage set
Unfortunately, that curse is now devastating all of the people in Eldraine
It's a three-mana (1R, 1W, 1U) 3/3 that gives Vigilance and Haste to any Hero who enters play while it is on the battlefield, until the end of the turn
For example, vehicles have their own variation with metal bars on the card borders, and as of Foundations all enchantments use the Theros enchantment creature frame
While the promotion is mainly intended for children due to it being packaged as a Happy Meal toy, many adults are buying up Happy Meals in bulk to get as many of these cards as possible