Nemesis Prime is a dark copy of Optimus Prime that appears in the web series Transformers: Wild King. In truth, Nemesis Prime is not a separate being but a guise adopted by the ancient dragon-like entity World Dragnus. Long ago on the planet Elementros, this evil was sealed away behind the Element Shield after seeking to wreak havoc and rule the planet. When the Energy Masters Optimus Prime and Megatron arrived on Elementros, World Dragnus recognized Optimus Prime as a threat and took on the form of Nemesis Prime in order to taunt and torment the Autobot leader. The entity first manifests as a strange figure that appears in Optimus Prime's mind after a near-death experience, born from a dark, twisted power. Nemesis Prime is characterized by a cruel and mocking personality, delighting in psychological warfare against his opponent. His primary motivation is to achieve destruction and ultimate control over Elementros, using whatever means necessary.

In the story, Nemesis Prime serves as a recurring antagonist who directly challenges Optimus Prime. He engages in confrontations such as a dark showdown with Shadow Megatron, and later reveals his true form as World Dragnus. Key relationships include his adversarial dynamic with Optimus Prime, as well as encounters with Shadow Megatron and other Energy Masters. Development sees the character begin as a mysterious mental apparition, then appear physically as a dark replica of Optimus, and finally ascend to his full dragon form. Notable abilities include the capacity to perform Wildocking with the Energy Beasts of Elementros and Worldocking with alien Energy Masters, using their energy as his own. He commands a force of obedient Dragknight Soldiers to augment both his robot and dragon forms through Wildocking. Lacking Element Energy of his own, he relies on his evil aura to power these combinations. Additionally, World Dragnus is capable of taking on the guise of other beings, which he uses to create the Nemesis Prime persona.