Three secrets that are not promo codes
Shared code lists will not finish these. Each one is a thing you pick up or read inside your own server.
Lobby telephone: Evil's Voice
A phone sometimes rings in the lobby. The sequence is 10 digits, randomized for that phone, with no hyphens. The yellow digit is the first digit. A code from a video or another server fails.
Turn on AFK so the next round does not pull you out of the lobby. When it rings, stand at the phone and write the digits down. Players often type them into chat without pressing enter. Then open the lobby code box and redeem that 10-digit string.
The rewards are the Banana Called badge, whose official line is "You better dial back," and the Evil's Voice skin: a black Banana with a red aura and a kill effect that spills bananas and bones. It does not cost Robux. Baker and Shark are the other skins called out for kill effects, and those two are passes.
Pink pastry: Nyan Cat Box
As a Runner, search floors for one small pink pastry. It does not spawn every round, and only one exists when it does. Pick it up the way you pick up cake. You leave a rainbow trail until the round ends, so Banana can follow the crumbs. Lockers and a quiet spot near an exit are the usual answer. If you are eaten, the pastry is gone for that round.
Surviving through the exits, or lasting until the timer ends, grants three permanent rewards: the Cosmic Pastry badge, the Nyan Cat Box skin, and the Nyan Pastry beacon. They are not tagged limited. You cannot collect the pastry while you are Banana.
The orange: Orange You Glad
An orange sometimes spawns on the floor for a Runner. Pick it up and still be holding it when you survive. Dropping it, or being eaten while you hold it, fails the attempt. One bite in Escape does not fail you by itself, as long as you still have a heart and you still have the orange. After 1:00 a single hit ends the run.
The official badge text is only "Orange you glad to have lived one more night?" The unlock described above also grants an Orange You Glad beacon. The orange's spawn chance is described as small, with no published percentage.
Golden Egg
SuperSecretSkin is a normal promo string, not a random phone code. The developer video for it says the Golden Egg stays available. Redeem it from the lobby like any other code. Spelling it wrong is the failure the comments on that video describe.