Zaxara, the Exemplary

Mana cost: {1}{B}{G}{U}
Type: Legendary Creature — Nightmare Hydra
Power / toughness: 2 / 3
Set: Commander 2020 #20 (mythic)
Price: $2.48 USD

Deathtouch
{T}: Add two mana of any one color.
Whenever you cast a spell with {X} in its mana cost, create a 0/0 green Hydra creature token, then put X +1/+1 counters on it.

Zaxara, the Exemplary has 3 printings, first in Commander 2020 (2020). EDHREC ranks it #5,842 among Commander cards. It appears most in Omnath, Locus of All decks (1,760 on EDHREC). 2 public decks on TCG run it. It has 5 official rulings.

Legality

commander: legal
legacy: legal
vintage: legal
pauper: not legal
modern: not legal
pioneer: not legal
standard: not legal
brawl: not legal

Public decks that run Zaxara, the Exemplary

Enhanced Evolution - Commander 2020, led by Otrimi, the Ever-Playful
Painbow - Dominaria United, led by Jared Carthalion

Commanders that run Zaxara, the Exemplary most

Deck counts from EDHREC.

Omnath, Locus of All: 1,760 decks
Progenitus: 1,326 decks
Jared Carthalion: 493 decks
Otrimi, the Ever-Playful: 289 decks

Often played with Zaxara, the Exemplary

Cards that show up in the same decks on EDHREC.

Rulings

2020-04-17: The Hydra token enters the battlefield as a 0/0 creature. Any abilities that modify or trigger on this event apply. After the token is on the battlefield but before any player can take actions, +1/+1 counters are put onto the token.
2020-04-17: If the spell you cast has {X}{X} in its mana cost, the token gets only X counters, not twice X.
2020-04-17: If X is 0, the 0/0 Hydra token will die immediately after the ability's done resolving unless something else is raising its toughness.
2020-04-17: The value of X in Zaxara's last ability is the value of X of the spell you cast.
2020-04-17: If an effect, such as that of Parallel Lives, causes Zaxara's ability to create multiple Hydra tokens, they each receive X +1/+1 counters.