The red-knee tarantula is a large terrestrial spider from Mexico.

Red-knee tarantula (Brachypelma smithi) on the 2015 Canadian Pet Expo.
Mexican red-knee tarantulas grow very large, leg span up to 6 inches, and can live for several years, the females even for decades. Mexican red-knee tarantula venom is considered to be mild, and for most humans it poses less danger than a wasp sting — unless someone is allergic to it.
Because of their impressive size and relatively mild venom tarantulas are often kept in captivity as ‘cool’ pets. The Mexican red-knee tarantula is considered to be a very good beginners’ tarantula because of its modest needs. So if you are considering keeping spiders as pets the red-knee tarantula is a good species to start with.
Further Readings:
Brachypelma smithi – Mexican Redknee Tarantula Caresheet.
Beginner’s Guide to Tarantula Care.