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Mossborn Hydra

Creature — Elemental Hydra

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
This creature enters with a +1/+1 counter on it.
Landfall — Whenever a land you control enters, double the number of +1/+1 counters on this creature.

CMC
3
Mana cost
{2}{G}
Color identity
G
Rarity
rare
Set
Foundations Promos
Price
$17.52
EDHREC rank
#860
Buy on TCGplayer
Mossborn Hydra card art
Mossborn Hydra enters with a pile of +1/+1 counters and puts a counter on itself every combat — raw, self-sustaining pressure that closes games without needing setup. The cost is that it asks a lot of you in the command zone or support slots, and shells built around Agatha's Soul Cauldron or Bristly Bill, Spine Sower are where it earns that ask.

Best Commanders

Commanders with the highest synergy

01
Bristly Bill, Spine Sower

Bristly Bill, Spine Sower

66.8% of decks · synergy 0.53

Bristly Bill, Spine Sower doubles every counter Mossborn Hydra places on itself, which means each combat step produces two counters instead of one — the Hydra becomes the deck's primary clock without any additional investment.

02
Gargos, Vicious Watcher

Gargos, Vicious Watcher

54.3% of decks · synergy 0.40

Mossborn Hydra is a Hydra, so Gargos, Vicious Watcher slashes its cost and fights down blockers the moment it resolves, giving the Hydra a clear board to grow into on the very next turn.

03
Loot, Exuberant Explorer

Loot, Exuberant Explorer

54.5% of decks · synergy 0.40

Loot, Exuberant Explorer generates the excess mana that makes casting a large Mossborn Hydra feel free, and the landfall triggers stack naturally with the Hydra's counter accumulation to keep the clock accelerating.

04
Omnath, Locus of the Roil

Omnath, Locus of the Roil

41.9% of decks · synergy 0.39

Omnath, Locus of the Roil converts each landfall event into a damage ping or a card, and Mossborn Hydra's counter count is high enough that Omnath's power-matters trigger fires at a meaningful number, tying the two engines together cleanly.

05
Zimone, Paradox Sculptor

Zimone, Paradox Sculptor

43.4% of decks · synergy 0.36

Zimone, Paradox Sculptor rewards playing multiple lands per turn with extra card advantage, and the mana surplus that strategy produces makes Mossborn Hydra's X cost trivial — the Hydra lands big and Zimone keeps the hand full.

Format Analysis

Where it lives, where it can’t

FormatVerdict
commander legal
legacy legal
modern legal
pioneer legal
standard legal
vintage legal
pauper not legal
oathbreaker legal

Commander is where Mossborn Hydra lives — the singleton format's slower clock and multiplayer life totals give the Hydra time to grow, and the abundance of +1/+1 counter synergies in green make it a natural fit. In competitive 60-card formats like Modern and Pioneer, it has no realistic path: six mana for a creature with no immediate protection is unplayable in those contexts, and it would need to be an immediate four-for-one to justify the slot. Standard is technically legal but the same logic applies — Mossborn Hydra wants a game that lasts long enough for its combat trigger to matter more than once. Stick to Commander.

Key Combos

Combo lines featuring this card

Budget Alternatives

Cheaper options that do most of the same work

If Mossborn Hydra is out of budget, Managorger Hydra does the core job — a Hydra that grows every time any player casts a spell — for under a dollar, though it lacks the guaranteed combat trigger and starts smaller. Vastwood Hydra costs almost nothing and at least goes wide on death, but it trades Mossborn's sustained counter generation for a one-time distribution effect that only matters when it dies.

Price Context

Current price

$17.52 mid tier

At $17.52, Mossborn Hydra sits in mid-tier pricing — expensive enough to feel like a deliberate slot, cheap enough that the Bristly Bill and counter-doubler shells justify it without wincing. It's a card with a narrow but loyal home, so the price reflects real demand rather than hype; it's unlikely to spike further without a new Commander precon or a major rules change.

Explore

Sources

Mentioned

← All cards

Updated . Data from Scryfall, EDHREC, and Commander Spellbook.