A floating pie, a secret song and the mind-altering power of drugs: Some of today's most popular video games feature some of the best "easter eggs," hidden secrets and quirks that developers hole away for discovery by curious and resourceful players.

Here are five such tricks and treasures.

"Dragon Age: Inquisition": Bioware's fantasy role-playing game is intentionally massive. Players can go almost anywhere — wide deserts, deep forests and ancient crumbling castles. Players can even go a few places they might not expect.

Kotaku's Patricia Hernandez explains: "If you happen to fall through the map in the exact right place in 'Dragon Age Inquisition,' you might find something a little weird."

That place is in Skyhold, your main character's base of operations in the game. The room itself is missing one wall and looks like you shouldn't be there; a piece of pie wearing a top hat floats in the air as jewelry box music plays. Even stranger: The game's developers have teased that "Inquisition" has more than one such secret location.

Intrepid audiophiles also have uncovered what they claim is a hidden addition to the game's story.

"Mario Kart 8": A long-standing piece of Nintendo lore again turns up in the company's latest party racer: A yoshi on the map "Yoshi Valley" can be heard humming a 19-note refrain written by Nintendo composer Kazumi Totaka — a tune Totaka would go on to hide repeatedly in Nintendo games over the years, in increasingly elaborate ways.

The easter egg was first publicized by the YouTubers Somewhat Awesome Games. One note: You'll have to turn down the in-game musical theme in order to hear the yoshi singing.

"Call of Duty: Advanced Warfare": In the newest installment of the shooter series, in a particular building off a particular path in a particular map called Throttle, players can find — and then wield — a weapon called WEAPON_RPG.  (That means you probably weren't meant to find it, at the least.)

The gun is silent and it's glitchy, but it fires rockets all the same.

AH community has a complete rundown here.

"Grand Theft Auto V": The latest "GTA," which lets you drive what you want and shoot what you want, among myriad other legal and illegal activities, also features fully interactive peyote plants. Put another way, according to gaming blog Kotaku: "If you find one, your character will eat it — and then they'll trip out and think they've transformed into a chicken. Which means that you get to play as a chicken, albeit temporarily."

With some experimentation, players soon discovered that the in-game peyote allows them to play as all kinds of animals, including cats, dogs and seagulls.

"Destiny": Bungie's follow-up to its massively successful "Halo" series is itself a massive success, and like earlier Bungie games is also full of secrets. (As Business Insider notes, Bungie is no stranger to this: "In its contract with (video game publisher) Activision, there's even a stipulation that it must provide Activision with a list of all the Easter eggs.")

Eggs include hidden soccer balls, coded in-game maps and repeated references to Vladimir Komarov, which is perhaps less a secret than a very, very specific piece of information for a game about aliens in space in the future.