Mix together the ground beef, sausage, onion, saltine cracker crumbs, beaten eggs, and cajun seasoning in a bowl until well combined. In a large baking dish, form the meat loaf mixture into a Halfling shape, with a large head, 2 stubby legs, and 2 upraised arms.
Bake in the preheated oven until the meatloaf is no longer pink inside and just starting to turn brown, about 1 hour. An instant-read thermometer inserted into the center should read at least 165 degrees F (70 degrees C).
To decorate the meatloaf's head, pick out about 14 corn kernels, and arrange them into teeth.
Place 1 small green pepper slice on each side of the creature's head for ears; place two pickle slices on the face for eyes, then place 2 black olive halves, cut sides down, in the pickle slices to finish the eyes. One more olive half forms the nose. Surround the monster with a background of ketchup "blood," and bake until browned, about 10 more minutes.
Let the meatloaf rest for 10 minutes before serving. Just before serving, stick a paring knife in the meatloaf's body, and decorate it with a little ketchup blood.
