Abigail

"That's my twin sister, Abigail." - Wendy

Abigail is Wendy's twin sister, and as Wendy's perk, she will appear at least once every three nights. Abigail will defend Wendy by killing any hostile Mobs at night, but if Wendy comes too close to her, Abigail will damage and possibly kill Wendy. Abigail does try to keep her distance, however.

Using Abigail to kill mobs is an effective method to avoid being killed, however, Abigail can die during the night if she is killed by an enemy. When fighting a Ghost, Abigail will die simultaneously with the Ghost. If Abigail dies, she will not recur for at least 5 days.

Behaviour
Abigail is considered a hostile Monster, therefore not letting the player use a Straw Roll at dusk or at night.

Upon being dealt damage Abigail turns yellow. The player can force-kill her by dragging the weapons to her and when the attack sign shows, press on her. If she attacks Spiders, Pigs, or Beefalos, she will aggro the whole group. Abigail can also damage Spider Dens and Beehives.

Upon spawning, Abigail will kill anyone following the player including Smallbirds, but excluding Chester.

Abigail constantly moves in a straight line towards Wendy until reaching a safe distance and attacks with weak, but rapid attacks on anything occupying the same space as her, except for another Abigail spawned via console. This can lead to unintentional fights, ie accidentally attacking a killer bee hive, but can also be used to Wendys advantage. Simply skirting an enemy and leading her into it will lead her to kill it.

Origin
It was said by Kevin during a live stream that Abigail died under mysterious circumstances.

Trivia

 * Kevin has revealed that Abigail is jealous of Chester, and she used to kill Chester. This feature was removed in Doorway to Adventure Update.
 * Since Abigail is considered a hostile monster, pigs are hostile to her if she is spawned during the day.

Bugs

 * Abigail can spawn in daylight if a Straw Roll or if a Cooked Mandrake is used at dusk, right before she spawns.