Nightcrawler is an autonomous, mobile penetration testing agent designed to run entirely on a smartphone without cloud connectivity. Deployed on a rooted OnePlus 8 running Kali NetHunter, the system utilizes the device's Adreno 650 GPU via OpenCL to perform local inference using the LFM2.5-1.2B-Instruct-Heretic model (1.2 billion parameters). The agent operates through a continuous decision loop where the LLM selects targets and tools, which are then validated by a scope-enforcement proxy before execution via a Kali MCP server. The workflow includes reconnaissance, service enumeration, and exploitation using 27 pre-defined multi-step attack playbooks and a 24,956-entry CVE database. To maintain stealth, the agent employs slow scan rates (nmap -T2), host rotation, and cover traffic. For offline scenarios, it can perform WPA2 cracking using an external USB WiFi adapter. Performance metrics for the 1.2B model at Q8_0 quantization include a prompt speed of 115 tok/s and a generation speed of 13 tok/s. Despite a ~50% inherent command success rate for the small model, the system maintains stability through garbage detection, duplicate detection, and time-based context resets. Monitoring is handled via a web dashboard that provides real-time command feeds, network maps, and C2 controls.