Lightlong is an Energy Beast from the planet Elementros, specifically a giraffe-type Transformer wielding Lightning Energy that grants him control over thunder and electricity. His name reflects this elemental affiliation, stemming from "lightning," and he occasionally uses the first syllable as a verbal tic. He first encounters Optimus Prime when the Autobot leader arrives on Elementros searching for Megatron. Displaying immediate curiosity and friendliness, Lightlong explains that Energy Beasts embody one of five elemental energies—fire, water, earth, nature, or lightning—and introduces the concept of Wildocking, a combining process where Energy Beasts merge with larger robots called Energy Masters. When Megatron betrays Optimus and allies with the tyrannosaurus Energy Beast Captain Volca, Lightlong volunteers to Wildock with Optimus. This fusion creates "Lightning Optimus," enabling them to wield Lightning Energy offensively in attacks like the "Lightlong Slash." Lightlong's bravery and loyalty emerge during conflicts with the Dinosaur Tribe. After narrowly escaping Megatron and Volca, he guides Optimus to a cave refuge where they meet the elephant Energy Beast Hydrophant. Lightlong expresses concern over Hydrophant's timidity and later defends him from attacks by the dinosaur-aligned Spirituan and Ignite Leo. When Optimus is overwhelmed in battle, Lightlong initiates a triple Wildocking with Optimus and Hydrophant, forming "Lightning Aqua Optimus" to defeat their opponents, reinforcing his role as a unifier strengthening alliances within the Animal Tribe. Throughout these events, Lightlong references a local prophecy about a hero descending from the sky to wield elemental energies against evil. Believing Optimus is this destined hero, he remains steadfast in supporting him against Megatron's forces, showcasing optimism and dedication to protecting Elementros. Physically, Lightlong transforms between three modes: a robotic giraffe beast mode with articulated legs and neck, a humanoid robot mode standing approximately 10.8 cm tall, and a limb configuration for attaching to Energy Masters like Optimus or Megatron during Wildocking. His robot mode features 21 modular ports for attaching accessories or combination parts. He wields a detachable axe formed from his beast-mode tail and a "Lightning Energy" armor piece that integrates into combined forms. His core engineering is shared with other Energy Beasts, such as Captain Volca.