Nils, Discipline Enforcer [Commander 2021] Human Wizard Advisor Enchanted library is an artifact

Enchanted library is an artifact creature on the battlefield with power and toughness each equal to the number of cards in it

Golden-Tail headmaster

it's an artifact creature with power and toughness each equal to its mana value

put a +1/+1 counter on Nesting Dovehawk

Set: Diamond & Pearl: Legends Awakened Type: Lightning Rarity: Common Retreat cost: Colorless

Nils, Discipline Enforcer [Commander 2021] Human Wizard Advisor Enchanted library is an artifactSet: Commander 2021 Type: Legendary Creature Human Cleric Rarity: Rare Cost: {2}{W} At the beginning of your end step, for each player, put a +1 +1 counter on up to one target creature that player controls. Each creature with one or more counters on it can't attack you or planeswalkers you control unless its controller pays {X}, where X is the number of counters on that creature.