|First Appearance||Wazzup Blowup|
The Hidden Mustachios are hidden characters. After the episode Mystery of the Mustachios, Barry, Sombrero Mustachio, Middle Mustachio, Semi Far-Right Mustachio and Leader Mustachio have been secretly hiding in episodes, starting from Wazzup Blowup. The reason for this was a Facebook competition.
- Best Fiends Forever: Between the toaster and the bottle at 1:44/in the mess at the bottom left corner at 3:53.
- Annoying Valentines or Annoying Valentines (sitcom): Under Passion Fruit's right cherub wing, at 2:55 (normal) /3:44 (sitcom).
- ZOOM!: At 0:20 under the left hot plate (blocked by caption that says "Thumbs up for ZOOM!!!) /under the toaster at 2:40 while.
- Kung Fruit: At 0:52 in the hot plate right next to Midget Apple/At 1:35 on the right of Orange/at 2:04 in the bottom left corner.
- Rolling in the Dough: At 0:40 to the right of the toaster/At 2:09 a split second before Heel pops out of the toaster.
- Comedy Clubbing: On a chair at 1:56 and under a chair at 2:08.
- Annoying Orange Through Time 2: 0:25 on a tree and 0:45 right below the screen at the patch of grass below Orange.
- Mommy and Me: At 1:32 under the toaster while Mama Orange and Orange are annoying the crap out of Yam under the toaster 2:17 while Yam is being knifed on the toaster knob and under the hot plate on the stove.
- Juice Boxing :2:14 at the toaster and 2:50 beside the toaster.
- Fruit for All: At 0:15 on the lower right corner and at 1:46 on the steps near Banana.
- Flower Power!: At 0:00 at the very bottom on the bookcase.
- Trollin': At 1:15 on the toaster latch and at 3:47 behind Pear.
- YouTubers: 1:18 under the tripod and at 3:33 in the credits at Knife.
- Be a star!: 0:41 on Pear's camera for a half second.
- Orange Potter and the Deathly Apple: 1:01 behind Orange at the top-right.
- The Voodoo You Do!: 2:24 On a candle; 3:13 hidden right inside the O in the "annoyingorange.com" caption.