The mana value of a token that isn't a copy of another object is 0. A token that is a copy of another object has the same mana cost as that object.
17-04-2020
wotc
If a creature on the battlefield has {X} in its mana cost, X is considered to be 0.
17-04-2020
wotc
You choose odd or even while Extinction Event is resolving. Players can't take any actions between the time you make that choice and the time some creatures go extinct.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.