Ichorclaw Myr

Mana cost: {2}
Type: Artifact Creature — Phyrexian Myr
Power / toughness: 1 / 1
Set: Phyrexia: All Will Be One Commander #133 (common)
Price: $1.15 USD

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever this creature becomes blocked, it gets +2/+2 until end of turn.

Ichorclaw Myr has 2 printings, first in Scars of Mirrodin (2010). EDHREC ranks it #4,641 among Commander cards. It appears most in Urtet, Remnant of Memnarch decks (9,906 on EDHREC). 1 public deck on TCG runs it. It has 7 official rulings.

Legality

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

Public decks that run Ichorclaw Myr

Corrupting Influence - Phyrexia: All Will Be One Commander, led by Ixhel, Scion of Atraxa

Commanders that run Ichorclaw Myr most

Deck counts from EDHREC.

Urtet, Remnant of Memnarch: 9,906 decks
Ixhel, Scion of Atraxa: 2,294 decks
Ingris Stingerquill: 1,752 decks
Skithiryx, the Blight Dragon: 1,363 decks
Vishgraz, the Doomhive: 865 decks
Tetsuko Umezawa, Fugitive: 847 decks
Brokkos, Apex of Forever: 390 decks
Venser, Corpse Puppet: 351 decks

Often played with Ichorclaw Myr

Cards that show up in the same decks on EDHREC.

Rulings

2011-01-01: The -1/-1 counters remain on the creature indefinitely. They're not removed if the creature regenerates or the turn ends.
2011-01-01: Damage from a source with infect is damage in all respects. If the source with infect also has lifelink, damage dealt by that source also causes its controller to gain that much life. Damage from a source with infect can be prevented or redirected. Abilities that trigger on damage being dealt will trigger if a source with infect deals damage, if appropriate.
2011-01-01: Whenever Ichorclaw Myr becomes blocked, its last ability triggers just once, no matter how many creatures it became blocked by. It will get just +2/+2.
2011-01-01: A player who has ten or more poison counters loses the game. This is a state-based action.
2011-01-01: If damage from a source with infect that would be dealt to a player is prevented, that player doesn't get poison counters. If damage from a source with infect that would be dealt to a creature is prevented, that creature doesn't get -1/-1 counters.
2011-01-01: Damage from a source with infect affects planeswalkers normally.
2011-01-01: Infect's effect applies to any damage, not just combat damage.