Leech

Leech is a creature type used for cards that depict aquatic bloodsucking or carnivorous worms, sometimes used by physicians to bleed patients. Leeches prey on, and cling to, other creatures; they are parasites. They appear in all colors but primarily in black. The first creature to bear the type was Land Leeches from The Dark.

Leeches are not to be confused with Liches.

Homelands

 * The sorcery Leeches is the only card in Homelands to reference poison counters. In fact, this card removes poison counters, and yet the expansion contains no means for a player to gain poison counters.
 * Mark Rosewater hates it, because it can remove poison counters.

Invasion

 * Invasion had a cycle of rare leeches that are aggressively costed for the time period but with the drawback that all colored spells of its color that you play cost an additional mana of that color Alabaster Leech, Sapphire Leech, Andradite Leech, Ruby Leech and Jade Leech.

Associated cards

 * Leeches are the pets from the Leech Bonder.
 * Blessing of Leeches</c> is an aura that grants the ability to regenerate the enchanted creature, while losing 1 life each upkeep.
 * Mindleech Mass</c> is a creature made of mind-sucking leeches.
 * Other associated cards are Leechridden Swamp</c>, Leeching Bite</c>, Leeching Licid</c>, Powerleech</c>, and Thoughtleech</c>.

Trivia

 * Putrid Leech</c> is the only multicolored Leech.