Noun
oyster knife (plural oyster knives)
A knife with a short, thick blade, used to pry open oysters and separate the meat from the shell.
I do not weep at the world I am too busy sharpening my oyster knife. Zora Neale Hurston
A good, quality, sturdy oyster knife is a must for shucking, and you can generally pick these up where you purchase your oysters. Source: Internet
My personal favorite is the Duxbury oyster knife made by R. Murphy Knives, but you may find another one more comfortable and effective. Source: Internet