Grandpa Harley (initially known as Jade’s Grandpa) is a prominent background figure in Homestuck. As the genetic creator and guardian of Jade Harley, he lives an incredibly eccentric life on a secluded volcanic island in the Pacific Ocean. He is the absolute pinnacle of the "larger-than-life, globe-trotting adventurer" trope, but he is viewed through a deeply strange, comedic, and slightly unsettling lens.

Jade Harley is one of the four main human kids in Homestuck, acting as the Witch of Space. Raised on a remote volcanic island by her highly eccentric grandfather and her reality-warping dog, Becquerel, Jade is a crucial catalyst for the story. Visually recognized by her round glasses, buck teeth, and later, her canine traits after merging with her dog, she provides a unique blend of cheerful enthusiasm and immense, reality-bending power.

Dave Strider, the Knight of Time, is one of the four original human kids in Homestuck. Operating out of a skyscraper apartment in Houston, Texas, under the custody of his hyper-aggressive older brother, Dave is visually defined by his iconic aviator sunglasses, his broken-record t-shirt, and an unshakeable facade of cool indifference.