Fungus/Algae - the photosynthetic algae provides food for the fungus, which houses the algae

Termite/ Gut Bacteria -the bacteria break down the wood termites eat and give termites nutrition

Dog/Flea - flea feeds on a dogs blood and can carry disease or cause infection

Human/Tapeworm - the tapeworm lives in the small intestines and robs the human of nutrition

Shark/ Remora - Remora swim next to the shark to collect scraps. Shark doesn't care.

Cattle/ Egret - The egret follows the cattle to eat bugs stirred up by cattle walking.

Snowshoe Hare/ Lynx - The Lynx hunts the snowshoe hair for food

Moose/Wolves - Wolves hunt and eat moose.