An organism that gets its food by scavenging or stealing it from anotherorganism that it lives in close association with. ... (09 Oct 1997) ... 
Stealing food from an individual who has just obtained it. This is especially done by Magnificent Frigatebirds, Bald Eagles, and Parasitic Jaegers.
Bird that forages by stealing food from other birds (such as Parasitic Jaeger).
cleptoparasite, kleptoparasite 1. A hidden or unrecognized parasite. 2. An animal that obtains its food mainly by scavenging the food supplies of another species, especially one with which it habitually lives in close proximity.
an animal that steals food or prey from another animal.
An animal that steals food from another animal.