Basil Carlo, alias Clayface, is a metahuman criminal who was once a struggling movie actor prior to incarceration. His narcissistic personality drives frequent self-aggrandizement about his acting talent and perceived vital role in Task Force X; he routinely declares the squad's mission would collapse without him as the "protagonist." This egotism blends with a carefree, talkative demeanor that provokes irritation in teammates, especially Deadshot, resulting in frequent arguments. Despite his eccentricity, he proves perceptive as the first squad member to recognize their acquisition of special abilities upon entering the fantasy world and demonstrates unexpected strategic insight during missions.

His default appearance presents a humanoid form featuring deliberate Michael Jackson-inspired traits: dark yellow eyes, curly hair partially concealed by a white fedora with a black ribbon, and a formal white business suit layered over a brown vest, blue dress shirt, dark blue tie, and pocket squares. He consistently wears white dress pants, a brown belt with a silver buckle, and dark brown slip-on leather shoes. This form constitutes an aesthetic choice, not his original human likeness.

Clayface wields extensive metahuman abilities centered on his malleable clay physiology. His primary power enables complete shapeshifting for combat, espionage, or crafting functional weapons like blades from his own substance. This biology grants near-total physical invulnerability, allowing effortless regeneration of damaged or destroyed body parts. A key survival tactic is organ redeployment, permitting instantaneous relocation of vital organs like his heart or brain; this neutralizes Amanda Waller's implanted neck bombs, as he redistributes affected areas pre-detonation. Additional combat applications include immobilizing opponents by enveloping them in clay and employing superhuman strength destructively. His physiology exhibits vulnerabilities to water and magic, the latter exploited via restraining handcuffs during imprisonment. Entering the fantasy world granted him limited telekinetic control over environmental clay, though this ability remains underdeveloped.

Throughout the mission, Clayface engages uniquely with the isekai environment, openly expressing excitement over genre tropes like dragons, orcs, and heroic narratives while frequently referencing "plot twists" or "isekai logic." This contrasts teammates' reluctance or confusion, positioning him as an otaku-coded figure. His practical contributions include crucial discoveries about their enhanced abilities and participation in major conflicts, notably against the Undead King's forces. He achieved a significant survival feat when his neck bomb detonated; utilizing organ redeployment, he withstood decapitation-level damage. During the final battle, he received enchanted armor that amplified his capabilities via a magical transformation sequence. Despite his comedic relief role, his knowledge of fantasy conventions occasionally yielded tactical advantages.

Clayface maintains consistent disregard for mission parameters unless personally intrigued, prioritizing exploration of the fantasy realm's mysteries over Waller's directives. This autonomy stems from his bomb immunity and self-absorption, though shared combat experiences fostered reluctant camaraderie with teammates. His character arc lacks traditional redemption, focusing instead on opportunistic self-interest throughout.