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Horseshoe Crab

Creature — Crab

{U}: Untap this creature.

CMC
3
Mana cost
{2}{U}
Color identity
U
Rarity
common
Set
The List
Price
$0.20
EDHREC rank
#11673
Buy on TCGplayer
Horseshoe Crab card art
Horseshoe Crab is a three-mana 1/3 that untaps itself for a single blue mana — irrelevant on its own, but the backbone of infinite-untap loops in combo shells. Experiment Kraj and Mairsil, the Pretender both treat it as a core engine piece, not a filler creature.

Best Commanders

Commanders with the highest synergy

01
Mairsil, the Pretender

Mairsil, the Pretender

52.5% of decks · synergy 0.52

Mairsil, the Pretender exiles Horseshoe Crab to cage its untap ability, then uses that ability to untap itself and fire off caged activated abilities an arbitrary number of times in a single turn.

02
Charix, the Raging Isle

Charix, the Raging Isle

39.5% of decks · synergy 0.39

Horseshoe Crab shares the Crab creature type with Charix, the Raging Isle, making it a tribal inclusion — and its self-untap ability gives Charix a way to attack and still hold up blockers or trigger repeated tap effects.

03
Mimeoplasm, Revered One

Mimeoplasm, Revered One

22.5% of decks · synergy 0.22

Mimeoplasm, Revered One can enter as a copy of Horseshoe Crab with +1/+1 counters stacked on it, and the self-untap ability turns those counters into a repeatable threat engine when paired with tap-synergy payoffs in the graveyard.

Format Analysis

Where it lives, where it can’t

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

Horseshoe Crab sees essentially zero play in Legacy, Vintage, or Modern — the self-untap loop is too slow and too creature-dependent to compete in those formats. Pauper is the one non-Commander format worth noting: infinite-untap combos are viable at common power levels, and the Crab has seen fringe use there. Commander is where it actually matters, exclusively in combo decks that need a repeatable untap outlet on a permanent.

Key Combos

Combo lines featuring this card

Price Context

Current price

$0.20 bulk tier

At $0.20, Horseshoe Crab is deep bulk — you're picking it out of a junk bin, not buying it off a vendor page. Demand is narrow enough that the price won't move; grab it when you need it and don't think twice.

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Sources

Mentioned

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