A multifunctional cutter, including a shank, a blade, and an adjustment assembly is provided. A front side of the shank is provided with a cutting area, and an inner cavity of the shank is respectively communicated with a front end of the shank and the cutting area. The blade is detachably mounted at a front portion of the adjustment assembly. The adjustment assembly is mounted in the inner cavity, and the adjustment assembly is configured to drive, under driving on an outer portion of the shank, the blade to slide along the inner cavity. The blade is configured for providing different functions when the blade moves to different locations.

A knife, components thereof, a sheath therefor, and associated methods. The sheath may be releasably retainable on the blade by engagement of connection structure of the sheath and blade formed by inserting the blade into the sheath. The blade may include a bottle opener. The knife may include a finger recess adapted to receive a finger of a user when the knife is gripped by the user. The knife may be an ulu knife.

A multi-functional knife is provided, including: a housing provided with an accommodating cavity and an opening, where the opening is provided at a front end of the housing; a blade holder configured to hold a blade and removably accommodated in the accommodating cavity; a first guide assembly including a first guide rail and a drive member which is drivably connected to a front side of the blade holder to cause the blade holder to move along the first guide rail; and a second guide assembly including a fixed surface and a second guide rail provided on the fixed surface. A rear side of the blade holder is pivotally connected to the second guide rail to cause the blade holder to move along the second guide rail.

A knife, components thereof, a sheath therefor, and associated methods. The sheath may be releasably retainable on the blade by engagement of connection structure of the sheath and blade formed by inserting the blade into the sheath. The blade may include a bottle opener. The knife may include a finger recess adapted to receive a finger of a user when the knife is gripped by the user. The knife may be an ulu knife.