Answer
The creature Luigi Galvani used in his bioelectricity experiments was the frog. Galvani observed that when he touched the frog's nerves with metal, the frog's leg would twitch. This led him to believe that electricity was responsible for muscle contractions. Galvani's work was the first to show that electricity could be used to stimulate muscle contractions, and it laid the foundation for the field of electrophysiology.