The crooked knife is a one handed drawknife, and the term "crooked" referes as far as I understand it to the handle, not the blade. Because I have images of crooked knives with straight blades. The crooked knife is used to make many objects, from canoes and canoe paddles to wooden spoons. The unique shape of the handle enables the user to assert a lot of power safely but just flexing the wrist.
I just made a crooked knife this morning out of the blade from a hoof scraper which I had to heat and reshape and then harden again, and a piece of wood cut from some dead pussy willow. I carved out the recess for the blade after final reshaping of the handle. The blade I secured to the handle with two brass screws. Then I bound the whole with wet rawhide and let it dry. Wet rawhide is flexible and stretches a little. When it dries it shrinks and hardens.
Crooked Knife 1720-1800.