In the novel, Percy learns that he can speak to horses and other equine species, due to the fact that his father created them. He learns this while communicating with a zebra while riding in the Kindness International trailer. In this episode he doesn't meet up with the zebra, so Percy has yet to learn about this ability.
In the novel the trio isn't aware of the lotus flowers, or that they could get trapped. Here, they proactively take precautions not to eat anything.
In the episode, Percy and Anabeth find Grover playing a VR game when they are ready to leave the Lotus Hotel. This is almost taken completely from the novel, as they find him playing a reverse hunting game, in which the animals hunt humans.
This episode marks the first time that Percy calls Annabeth Wise Girl. This is his nickname for her in the novels.
Hermes makes his second appearance in this episode (the first being in episode 3). In the novels, he doesn't make his first appearance to Percy until book 2 The Sea of Monsters.