# AI Just Put Black Ops Zombies Inside GTA V > Source: > Published: 2026-10-12 14:07:55+00:00 ## A prompt turns GTA into a zombie arcade AI just performed a surprising feat: it rebuilt **Call of Duty of Duty: Call of Duty: Black Ops 3 Zombies** inside of *Grand Theft Auto V*. The demo features a full-fledged zombie arcade around the iconic Vinewood sign, complete with escalating rounds, a wall-mounted Ray Gun, the Juggernog perk machine, and a Mystery Box. This was orchestrated by **Universal Modder**, an open-source toolkit and Claude Code plugin developed by Rehan Sheikh Sheikh. Universal Modder’s setup is an elegant host-and-guest system. *Grand Theft Auto V* Story Mode served as the host, running the mod through ScriptHookV with anti-cheat disabled. *Call of Duty of Duty: Call of Duty: Black Ops 3*, conversely, was treated as a read-only guest; the AI agent accessed its files for reference but never launched or altered the game itself, preventing anti-cheat flags. Using Claude [Claude Opus](https://www.stork.ai/en/claude-opus-4-6), the prototype delivered a functional, albeit visually eclectic, experience. While points, rounds, and perk behavior worked as expected, the mod mixed native *GTA V* assets with AI-generated look-alikes for machines like Juggernog and the Mystery Box. The result was a compelling visual approximation rather than a pixel-perfect port of *Call of Duty: Black Ops 3* models, though authentic sound effects, like the Juggernog jingle, were extracted and integrated. ## The agent does more than write code Universal Modder, an open-source toolkit by Rehan Sheikh Sheikh, transcends simple code generation. Built around a CLI, agent skills, and a knowledge base of prior modding notes, it acts as an autonomous engineering team, not just a programmer. The agent orchestrates a complex workflow. It first performs recon, checking game and loader compatibility (e.g., GTA V with ScriptHookV), backing up saves, and inspecting existing code. Then, it splits research across specialized sub-agents. This distributed intelligence tackles unusual engineering challenges. One sub-agent analyzed Call of Duty: Black Ops 3 sound banks, deciphering their storage format to write a custom converter. This allowed the mod to use authentic round change, Juggernog jingle, and "kaboom" sounds directly from the guest game. Another sub-agent navigated GTA V’s strict model loading limitations. Since the game cannot simply load new 3D assets, the agent devised a **ReShade-based rendering workaround**. This solution draws custom models, like the Mystery Box or perk machines, using GTA’s camera and depth buffer, effectively projecting them into the game world rather than injecting them. The system even optimizes its own development loop. Recognizing GTA V’s slow load times, it split the mod into gameplay code that could **hot-reload** in just 5 seconds, using this capability nearly 50 times for rapid feature testing and iteration. ## The magic comes with visible seams Universal Modder’s output presents a fascinating blend of authentic and synthetic elements. Real **Call of Duty of Duty: Call of Duty: Black Ops 3** audio, like round change jingles and the "Kaboom" sound, was extracted directly from the guest game. Zombie stats and scaling came from decompiled scripts and wikis. However, the agent generated other assets. Perk-machine art, including the Juggernog machine with slightly garbled text, and the Mystery Box model, were synthesized via [Fal.ai](https://www.stork.ai/en/fal-ai). The "zombies" themselves were just GTA V NPCs, and the weapons were standard GTA V firearms, albeit with **Ray Gun** mechanics recreated using GTA's projectile system and authentic sounds. Iteration was key to the mod's development. The agent wrote roughly 4,000 lines of C++, hot-reloading gameplay code nearly 50 times in the running game to check features. Screenshots helped it verify implementation, overcoming GTA V's slow load times by splitting the mod for rapid iteration. This experimental demo required a specific setup: GTA V Story Mode with anti-cheat disabled, running through the ScriptHookV mod loader. According to the video, the entire process cost about $68 in Claude Claude Opus API tokens and a few additional dollars for the generated Fal.ai art. For those curious about the underlying code, the project is open-source at [GitHub - Rehan Sheikh-remade/universal-modder](https://github.com/RehanSheikh-remade/universal-modder). Enjoying this? Get one like it in your inbox each morning. one email a day · unsubscribe in two clicks · no third-party tracking ## A modding breakthrough, not a finished game Universal Modder compresses a complex workflow, accelerating tasks that traditionally demand specialist modding knowledge. An agent can now handle: - Reconnaissance - File-format investigation - Asset work - Coding - Testing Results like the *Call of Duty of Duty: Call of Duty: Black Ops* *Zombies* mod in *GTA V* showcase a breakthrough, yet they are not finished games. Viral AI mashups often remain short-lived spectacles, not polished products. Rendering workarounds and generated assets, while impressive, can leave obvious fidelity and stability gaps. The generated Juggernog text and GTA V NPCs in the demo illustrate this, contrasting with the authentic *Call of Duty of Duty: Call of Duty: Black Ops 3* audio. Crucially, shared field notes help future agents learn from fixes, documenting "gotchas" and solutions for complex scenarios like *GTA V*'s model loading. The tool’s single-player and read-only guardrails for guest games like *Call of Duty of Duty: Call of Duty: Black Ops 3* are vital. These guardrails address anti-cheat and game-integrity concerns, ensuring this powerful automation remains a tool for creative exploration rather than exploitation. ## Frequently Asked Questions ### What is Universal Modder? Universal Modder is an open-source toolkit and Claude Code plugin that helps AI agents inspect games, build mods, and test them. ### How did the demo put Black Ops Zombies in GTA V? The agent used GTA V as the host game, read Black Ops 3 files for reference, and built zombie-round mechanics, sounds, and visual overlays for Story Mode. ### Does Universal Modder use original game assets? Some elements used real Black Ops 3 sounds, while models were generated look-alikes because the extraction process would have required launching the guest game. ### Is Universal Modder safe to use in multiplayer? The demonstrated setup was for GTA V single-player with anti-cheat switched off, and the guest game was read-only. Do not use mods in protected multiplayer.