Widow

Widow is a boss that can appear in.

Behavior
Widow makes large leaps towards Isaac, at approximately double the distance of Monstro, and can perform the following attacks after landing:
 * Leaves a puddle of White Creep and spawns a Sack.
 * There is a maximum of 2 Sacks alive at once. This was changed to 3 in X update.
 * Spits out a Spider.
 * Widow can kill her own Spiders and Sacks if she jumps on top of them.

Champion Versions

 * Black: Spawns Big Spiders instead of Sacks, Black Creep instead of White, and spits out six blood shots instead of Spiders.
 * Pink: Spawns Boils instead of Sacks and Attack Flies instead of Spiders. Jumps quicker. She is also 50% smaller.

Trivia

 * Widow was added in the Wrath of the Lamb DLC for the original The Binding of Isaac.
 * She is the boss version of the Trites.
 * The Wretched is the posthumous version of her.
 * The name probably refers to the Latrodectus, commonly known as "black widow spider".
 * Widow's and The Wretched's animations and behavior have been sped up to more closely resemble their Flash counterparts.