A rubber ducky is a toy shaped like a duck that is usually yellow with a flat base. It may be made of rubber or rubber-like material such as vinyl plastic. Rubber ducks were invented in the late 1800s when it became possible to more easily shape rubber, and are believed to improve developmental skills in children during water play. The yellow rubber duck has achieved an iconic status in Western pop culture and is often symbolically linked to bathing. Various novelty variations of the toy are produced, and many organizations use yellow rubber ducks in rubber duck races for fundraising worldwide.

However, the term "rubber ducky" can also refer to a potentially nefarious hacking tool. The USB Rubber Ducky is an HID (Human Interface Device) that looks similar to a USB Pen drive. It may be used to inject keystrokes into a system, used to hack a system, steal victims essential and credential data, and inject payloads to the victims computers. The USB Rubber Ducky looks like an unremarkable USB flash drive to the human eye, but when you insert it into a computer, the machine sees it as a USB keyboard, which means it accepts keystroke commands from the device just as if a person was typing them in. The programming language, dubbed DuckyScript, is a simple instruction-based interface to creating a customized payload. The USB Rubber Ducky can be used for targeting vulnerable systems or programming processes and saves time. It is a favorite device of hackers and penetration testers as it is very fast and cannot be detected by any Anti-Virus or Firewall as it acts as an HID device.