Puck, an Artificial Spirit crafted by Echidna in the Re:Zero universe, bears the titles Beast of the End and current Great Spirit of Fire. His spirit form manifests as a small gray and white cat with a pierced left ear. Mischievous and playful by nature, he maintains a happy, easy-going demeanor while offering friendly advice to Emilia. Puck adapts swiftly to new situations, prioritizing Emilia’s contentment and engaging in lighthearted activities. As one of his world’s most powerful spirits, Puck commands formidable ice-based magic. He generates ice storms, summons massive ice crystals, and freezes targets instantly—exemplified when he killed Subaru Natsuki with a mere glance in their original world. His abilities extend to enhancing others’ magic, such as augmenting Emilia’s power during a dodgeball game. Puck shares an enduring pact with Emilia, persisting into the new world; their bond is evident when Emilia considers gifting him for Valentine’s Day. He interacts frequently with Subaru Natsuki, fostering a chummy, buddy-like dynamic. Puck assessed Subaru’s magic affinity, attempted to teach him, and later expressed curiosity about Subaru’s hidden talents in the new world. He teases Subaru relentlessly, mocking his fear of detention with quips like, "Don’t lie, I bet you’re into that, you freak." Puck collaborates with cross-series characters, including Tanya von Degurechaff during special training for Kazuma Sato’s field day. When Roswaal introduces Chomusuke as a transfer student, Subaru presents Puck as an official Class 2 student. Across all seasons, films, and spin-offs, Puck’s interactions and traits remain defined solely by these documented instances. His role persists unaltered as Emilia’s supportive companion and a secondary participant in group activities.