Daxos the Returned

Legendary Creature — Zombie Soldier    (CMC:3)

Whenever you cast an enchantment spell, you get an experience counter. : Put a white and black Spirit enchantment creature token onto the battlefield. It has "This creature's power and toughness are each equal to the number of experience counters you have."

098 PZ1 • ENAdam Paquette

™ & © 1993— Wizards of the Coast

Notes: TODO: Check rarity

Legal in: Legacy,Vintage,Freeform,Prismatic,Tribal Wars Legacy,Singleton 100,Commander

Oracle Text (click to copy):

11/4/2015
The power and toughness of the tokens will change as the number of experience counters you have does.
11/4/2015
The ability that defines the token’s power and toughness is part of the token’s copiable values. Copies of the token will also have that ability.
11/4/2015
Putting an enchantment creature token onto the battlefield won’t cause Daxos’s first ability to trigger. On the other hand, constellation abilities trigger whenever an enchantment enters the battlefield under your control, so those abilities will trigger.
11/4/2015
Experience counters are the second kind of counters a player can have, joining poison.
11/4/2015
All experience counters are identical, no matter how you got them. For example, the last ability will count experience counters that you got from the first ability, from another ability, from proliferating, and so on.
11/4/2015
Each game pack includes a card labeled “Experience” with the suggestion “Place your experience counters here.” This card isn’t required for play. It’s simply a convenient spot to put your experience counters, which can be represented with dice, glass beads, or other small items.