Harry is Lain Valhalla's hedgehog companion, characterized by brown quills, light grey fur, a pink snout, and black eyes. He displays aggressive tendencies toward others, often snarling and flaring his quills, but exhibits fierce loyalty to Lain. Harry is frequently seen perched on Lain's shoulder or tucked into his fur collar, receiving gentle strokes of affection.

His flared quills bear a distinct resemblance to Lain's hair. Harry holds the distinction of being the third pet introduced in the Beyblade Burst series, following Carl in *Beyblade Burst Evolution* and Tango's Cat in *Beyblade Burst Rise*.

Unconfirmed speculation within the blading community suggested Harry might have perished during a tournament finals match, theorizing an incident where Lain's beyblade, Lucifer, could have struck him. This potential event was proposed as a catalyst for intensifying Lain's "Flare" ability and evolving Lucifer. Harry appeared alongside Lain in the final battle of the manga (*Beyblade Burst Comic Vol. 18*), facing Hyuga Asahi using Hyperion Burn against Lain Valhalla using Lucifer The End. His role remains consistently defined as Lain Valhalla's companion animal within the depicted events.