Eastern Massasauga
Sistrurus catenatus
- Least concern
- Card rarity: Common
- Reptiles

The eastern massasauga is a species of rattlesnake found in eastern North America, from southern Ontario, Canada, eastern regions of the Midwestern states, and parts of the Great Lakes region in the United States. Like all rattlesnakes, it is a pit viper and is venomous; it is the only species of venomous snake in Ontario.
Classification
- Class
- Reptilia
- Order
- Squamata
- Family
- Viperidae
- Genus
- Sistrurus