Nails The Spider (voiced by Charles Alder) is an anthropomorphic spider who serves as Frank Harris' partner. In Jaden goes to Cool World, he and Berkeley Beetle try to stop Holli Would from leaving Cool World, but they get "penned" (sucked into a pen). But they both escape in the end. And Nails asks to join Jaden's team, and he accepts. He is the most loyal member of the team.
- A running gag in the series is Nails getting trapped within fountain pens by villains.
- Nails will meet Jeffrey and his team in Jeffrey & Friends enter Cool World. Although Jeffrey is scared of spiders, Nails will be the one spider that he isn't afraid of.
- Nails' self-proclaimed and unofficial duty for the group is to prevent anyone from harming Jaden's and Alexis' relationship.
- Nails is allergic to clouds.
- Nails also acts as a protective guardian to Xion and defends her from bullies like Cleo and her posse.
- Nails is a old friend of Sam and Max.