Derpy Hooves, the fan-favorite pegasus with crazy eyes, appears for the first time as a klutzy character (as a nod to the Bronies) instead of the random background pony she had been until this episode. She can be seen at 11:09, accidentally dropping items on Twilight Sparkle.
Rainbow Dash and Rarity were both absent in this episode, but Rainbow was mentioned.
Friendship Report: Twilight learned even though she can't understand something random from someone else, it doesn't mean she can't believe them about it.
When Twilight becomes enraged upon learning the hydra wasn't the doozy Pinkie predicted, she takes on an appearance which resembles the Pokemon character Rapidash.