Zaxara, the Exemplary is a mythic Legendary Creature — Nightmare Hydra card from Commander 2020 (C20), collector number 20. Current market price: $2.36 (foil $3.46), TCGplayer market prices via Scryfall.
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.