Killer Croc, also known as Waylon Jones, appears in Suicide Squad ISEKAI as a formidable member of Task Force X. His defining trait is his inhuman, reptilian appearance; he is a crocodile-like human possessed of extreme physical strength, which is augmented by remarkable speed and power that allows him to conquer the underwater realm. His character design and abilities are rooted in a rare condition that gives him a scaly hide, and he is a classic antagonist from the Batman mythos, often depicted as a super-criminal who embraces his monstrous appearance after a lifetime of being ostracized for it.

In the context of the Suicide Squad ISEKAI narrative, the character is transported alongside other villains into a fantastical other world, where his role expands significantly. While his primary function within the Squad is to serve as a powerhouse, his abilities are particularly suited for aquatic combat. In this new environment, he is depicted not just as a brute, but as a commander who gains control over a large sea monster named Leviathan. This creature, which is over ten meters long and capable of following complex commands, becomes an extension of his dominance over the water. His authority is such that he can command the monster to swim in circles to create a massive geyser or whirlpool, which he can then surf on to attack his enemies.

His personality is shaped by his primal and carnal nature. Having been treated as a monster for most of his life due to his appearance, he has reversed this abuse into a source of strength. Instead of hiding in the sewers out of shame, he proclaims the underground as his kingdom. His ultimate goal is to attain power and respect, not just through fear, but to force others to accept him. In the isekai world, this drive manifests as a strategic mindset, as he leverages his magical abilities and command of a leviathan to establish his strength. He does not rely on formal martial arts; instead, he fights using his overwhelming strength, sharp claws, and teeth in close quarters.

His key relationships within the Squad are defined by the shared predicament of being imprisoned criminals forced to work together. However, his narrative development is marked by his adaptation to the new world. Upon arriving in the other world, magical energy flows through his body, granting him the ability to utilize various artifacts and magical items. This development enhances his already impressive physical capabilities, which include superhuman strength to tear through steel and walls, durability to withstand blades, and regenerative abilities to heal from serious wounds. As an amphibian, he is as comfortable in the water as on land, capable of holding his breath for extended periods and leaping dozens of meters out of the water in a single bound.