Book 1
This is the first chapter to have a bot that is not a member of the Piggy family
Forest (The bot is Sheepy)
This map has the first track bot ever in Piggy.
Sewers (Alfis)
This is the most expensive skin in the Book 1 category
Budgey
Yo this some free points to whoever says "Piggy" first.
Nice here you go.
This was the first map in the actual "Extra Chapters" category.
The Hunt
You meet up with Mr. P at the end of which map?
School (In the sewers)
This is the skin you unlock by doing a secret in Temple.
Phenna
This skin was released to go with the 6th Annual Bloxy's event
Gold Piggy (best skin btw)
You can see this character's shadow in the window of a building on City. This is the only time this character appears in game.
Mrs. P
This was the first Book 2 extra chapter
Heist (Winter Holiday is also kinda the right answer)
The name of the song that plays during the second phase of plant (Double points if you name the artist)
For You To Stay by Mira K
TIO is introduced at the end of this chapter.
Temple (savior ending)
This is the only Book 1 skin that has a song composed by BSlick
Poley
Poley was the first ever secret released skin as a part of a collaboration with this Roblox game.
Jailbreak
This was the first official extra chapter. It also is the only story-related chapter without a specific space in the timeline.
Distorted Memory
This was the first new game mode besides Player + Bot
Infection (Released with Metro)
This is the only chapter besides Lab where you escape without a key.
Factory
If you use this skin I will come to your exact coordinates at night and lock you in my basement forever.
TIO
You unlock three clothing items after completing this secret.
Maple Donut
This chapter was waited on for a while, and focuses around a fan-favorite character.
Decay
The end cutscene of this chapter is said to be the biggest plot twist in all of Piggy. Yes, even bigger than anything Book 2 related.
Mall (When you find George)
Beat Docks without Pony getting hit, enter code in Camp on Swarm, unlock the 4 vents on Lab on Bot, enter the code, and complete TIO's hallucination.
Good job if you got that.
This skin was the first ever season released skin.
Anteo
The Silver Paw was teased in this chapter.
Carnival
In Decay, there's a diary left in the Metro (Where you use Shovel) written by this character, who wasn't canon until then.
Laura