Amadeus the Firstborn

Amadeus, the Firstborn is the first boss of struggling. She is a post-laboratory abomination god and the first Abomination God encountered in the game. She is seen in the cave chapter.

Location
Amadeus is encountered just after On the Steps of the Firstborn. Throughout this level and late in the level before it, Amadeus can be heard singing distantly. At the end of On the Steps of the Firstborn, Troy will fall down and get stuck on what looks like a giant muscle tendon. An enormous eyeball will open up and look at them, causing Troy to scream in fear. The camera zooms out to show Amadeus in full, chattering her teeth. The thing that looks like a person shoved into a blender will then scream, destroying Troy's arms. After this brief introduction, the battle will begin.

Appearance
Even though Amadeus is revealed to be friendly, her physical appearance is far from inviting, even compared to the other abominations in the world of Struggling. She is a ginormous, grotesque mess of flesh and organs. Her body is shaped like a human heart, she has a massive brain that seems to have grown and tore its way out the top of her head, her face has a single eye and a large mouth, though it is far from her only eye. She has a long piece of flesh that dangles beside her, and lastly, an actual human heart can be seen in the center of the areas he is fought in. This heart is coated in a black cancer-like shell when she's first encountered, but it is a healthy red underneath. Though by far Amadeus's most notable trait is that she is only capable of speaking by singing and yelling like an opera performer.

Fight
As shown in the intro to the fight, the black cancer blobs around the room must be hit to clear the shell of of the heart in the middle of the room. Troy doesn't climb, and is instead able to control arms found around the room positioned similarly to pinball. Sphincters positioned around can push Troy into the cancer blobs to destroy them.

After all blobs are destroyed, the fight will end, and Amadeus will sing joyfully and emit acid, destroying the sphincter at the bottom of the room, allowing Troy to continue, as well as giving the first Abomination God Blessing that Troy can obtain: Remote Arms.

Additional Appearances
During the beginning of A Song of Acid and Bones, Amadeus can be seen in the background. She is also seen at the ending of the level, singing/screaming with everyone else. However, she does appear on posters during the basketball level. Also, she is seen after the credits in the final cutscene.

Speculation
Amadeus's voice may be made up of several recordings of different opera singers mashed together.

Trivia

 * Unlike the other abominations, who are named after characters from Greek mythology, Amadeus is named after Wolfgang Amadeus Mozart, a famous Austrian composer. Likely due to her cries of anguish sounding like singing.
 * The choir that can be heard during Amadeus's introduction is just saying "Amadeus." This is shared with Agamemnus, with the choir simply saying their name.
 * Amadeus at first appears to be stationary, but she is capable of moving, as can be seen during the ending cutscene of the Cave world where she suddenly appears in the background.
 * She is the oldest of the abomination gods, only ahead of Morpheus and Agamemnus, both 2nd and 3rd oldest respectively.
 * Adding onto that, she is also the hardest of the abomination gods and the 2nd hardest boss in the entire game.
 * The song that plays when you fight her is "Flesh Opera: Cries of the Firstborn"
 * When you turn the music down, it decreases the volume of not only the instrumentals, but also the vocals. Should you turn sound down, it decreases the volume of her screams.