Iconoclast -- Glossary
Symbiote: A living organism that lives in conjunction with another living organism, to their mutual benefit. A good example of a symbiotic relationship is the millions of bacteria that inhabit your intestines, allowing you to digest foods you would not normally be able to.
Parasite: A living organism that lives off of another organism (called a "host") which usually harms the host in the process. A good example of a parasite is a leech or a tick. Not all parasites harm their hosts, or are completely unwelcome. The remora which attaches itself to a shark's side is a parasite, as is a human fetus developing inside its mother.