Gurdy (ガーディ,Gādi) (also known as The Pile from the artbook) is one of the bosses found in The Caves from The Binding of Isaac and the Rebirth remake. She is a static boss that remains stationary in the middle of the room. When Isaac first enters the boss room, Gurdy is accompanied by a few Boils and Flies of random variety.
She is a small humanoid with a slight Isaac-resembled appearance inhabiting a huge pile of guts. In addition to her face, she is missing a left eye and her teeth look slightly crooked.
Gurdy's basic attack is firing five shots at once, in one of three different directions. This is indicated by her pulling her head inside, and making it reappear at another side.
Gurdy can also summon Attack Flies out of the pores on her body periodically to attack. On occasion, she will also spawn a Pooter/Fat Fly out of the larger pore on the right side of her body.
Lastly, she can summon two Boils (which can be replaced by a Gut or a Sack) at once in front of her, which is signaled by raising her arms.
Since Gurdy does not move, she is balanced out by having the highest amount of health (among all bosses in Caves and Catacombs) to take down. This means that any Items that improve Isaac's projectile damage output will shorten this fight significantly. This also gives Isaac a good time to use Bombs if he has any to spare, since he is guaranteed to hit and take a good chunk of health off of Gurdy.
It is preferable to take out any of the other monsters that Gurdy summons during the fight before focusing on her, so that they do not cause problems later on.
Sometimes, rocks will partially block Isaac's side paths, so that dodging Gurdy's shots becomes more difficult. It may be worth it to clear them with bombs at the start of the battle (and hurting Gurdy in the process).
Standing behind her will prevent her from firing her 5-way shot spread at Isaac, and most of the Boil shots will not reach him. However, Flies are still dangerous in this position.
Another good strategy is to kill all of the enemies first, and go to a side Isaac choose. That will cause Gurdy to shoot at him, but will take some time. Go to the other side to dodge her attack. Keep repeating, and Gurdy will be killed. This strategy will not work on the champion version.
If Gurdy spawns a Gut on one side of the room, the Gut's explosive shots can hurt Gurdy and whatever else she spawns.
In this form, she does not spew bullets; instead, she will continuously spawn various flies and boils.
In this form, she fires a wide spread of 16 blood shots. She also spawns eternal Boils but the Pooters she summoned will not be eternal.
The process by which Gurdy's head reappears when she performs her basic attack is described as "birthing" in the Unholy Edition art booklet.
Upon entering a room with Gurdy in it, the player will usually be teleported to the bottom center of the room regardless of which side the player entered from.
On page 18, Gurdy's appearance (from the bottom right) was going to sport with several bones and intestines sticking out of her guts.
Gurdy was confirmed to be female by Edmund on Formspring question regarding female bosses.
Gurdy appears in the demo of the original game.
According to Edmund, her name came from GERD (gastroesophageal reflux disease).
According to Edmund, Gurdy is based on a story centered around the D&D controversy in which a woman claimed she was thrown into a well filled with dead children; Gurdy was originally going to be composed of dead children (Isaacs, to be exact), but it was later decided to make her out of innards, to make it less confusing.
When Gurdy is frozen with a freezing item, the player will be able to push her. When she unfreezes, she will return to her original position.