Gyrus, Waker of Corpses

The amount of mana you spent to cast Gyrus is usually equal to its mana value, normally 3 plus the value chosen for X. However, you also include any additional costs you pay, including the commander tax.

If Gyrus enters the battlefield without being cast, then no mana was spent to cast it. It enters the battlefield without any +1/+1 counters. If no other effects are increasing its toughness at that time, it will be put into its owner's graveyard as a state-based action.

If another creature enters the battlefield as a copy of Gyrus, consider how much mana was spent to cast that creature to determine how many +1/+1 counters it enters with.

Gyrus's token copies exactly what was printed on the original creature card and nothing else. It doesn't copy any effects that modified it before it was put into your graveyard.

If the copied creature card has in its mana cost, X is considered to be 0.

Any enters-the-battlefield abilities of the copied creature card will trigger when the token enters the battlefield. Any "as [this creature card] enters the battlefield" or "[this creature card] enters the battlefield with" abilities of the chosen creature card will also work.

You choose which player or planeswalker the token is attacking. It doesn't have to be attacking the same player or planeswalker that Gyrus is attacking.

Although the token is attacking, it was never declared as an attacking creature (for the purposes of abilities that trigger whenever a creature attacks, for example).