Ixidron

As Ixidron enters the battlefield, turn all other nontoken creatures face down. (They're 2/2 creatures.)\r
Ixidron's power and toughness are each equal to the number of face-down creatures on the battlefield.

As this creature enters, turn all other nontoken creatures face down. (They're 2/2 creatures.)
Ixidron's power and toughness are each equal to the number of face-down creatures on the battlefield.

As Ixidron comes into play, turn all other nontoken creatures in play face down. They're 2/2 creatures.
Ixidron's power and toughness are each equal to the number of face-down creatures in play.

Commander 2019

As Ixidron enters the battlefield, turn all other nontoken creatures face down. (They're 2/2 creatures.)
Ixidron's power and toughness are each equal to the number of face-down creatures on the battlefield.