This is a full rundown of all 11 Quanty locations in Escape Academy 2: Back 2 School, and it’s aimed squarely at anyone who has swept the campus and still has one or two stubborn holdouts missing from the collection. I’ve split the list into two halves — the Quantys you meet on the natural story path, and the ones tucked slightly off the main route that are easy to walk right past.
The reason I put this together is simple: the optional Quantys are the ones that stall a completion run, and a few of them live in spots you’d never backtrack to on instinct. Going through them in the same order I actually encountered them keeps the search from turning into aimless wandering.

Story Quantys — The Ones You Can’t Miss
Six of the eleven Quantys sit directly on your Escape Academy course load, so they come to you rather than the other way around. The order below follows the point in the campaign where each one appears, which is the cleanest way to know whether you’ve already passed one or not.
Librarian Quanty — in the library, as the name suggests.

Warden Quanty — right by the door while you’re escaping detention.

Dance Instructor Quanty — in the dance studio, after you help Professor Chortkoff decide who gets to be in the play.

Curator Quanty — technically off the path, but he’s staring you in the face while you explore the upper arts section after dark.

Professor Quanty — next to Dr. Belinni in the weather tower.

Big Professor Quanty — appears after you plug Professor Quanty into his old lab processors. Surely he won’t use this for evil.

The Curator stands out as the odd one in this group — the source calls him technically off the path, and I’d treat that as a nudge to actually look around the upper arts section after dark rather than brushing straight through it. The others follow the story beats so closely that you’d have to be actively speedrunning to miss them.
Off the Path Quantys
The remaining five won’t cause much trouble once you know where to look — they’re just not sitting on the main route. I’ve listed these in alphabetical order so you can check your collection against the names in a sensible order.
Cashier Quanty — at the desk where you bought your books back in chapter 1.

Groundskeeper Quanty — just outside the hedge maze, to the right of the entrance (the opposite side from the brave student).

Janitor Quanty — inside the Escapist’s Time alcove near the window.

Lifeguard Quanty — on the beach in the little lifeguard hut. Personally, I don’t love the idea of an electronic being pulling me out of the water, since electricity and water don’t mix — but he’s effective at it.

Nurse Quanty — first floor of the headmaster’s tower. Very hard to miss this one, though technically missable if you’re a god gamer.

The Groundskeeper is the one I’d flag hardest to recall later — that right-of-entrance detail is the difference between finding him and circling the maze twice. If you’re stuck on a single missing Quanty, the Cashier and the Janitor are both tied to indoor spots you probably haven’t revisited since the moment they first showed up.
Working through both halves of this list should close the gap on the Quantys you’re missing. The story six are a quick sanity check against your progress, and the off-path five are the realistic culprits — start with the Cashier in chapter 1 and go from there.