Which hand saw is characterized by a short thin blade held by a bow-shaped frame for cutting irregular shapes?

The coping saw is characterized by its thin, flexible blade held in a bow-shaped frame, allowing for precise cuts in intricate and irregular shapes. This design is particularly advantageous for making curved cuts in woodworking and for tasks like creating detailed patterns or dovetails. The ability to replace the blade also adds to its versatility for different projects that may require varying thicknesses or types of blades.

In contrast, the utility saw is typically sturdier and designed for general cutting tasks; it's not specialized for intricate patterns. The keyhole saw, while also a tool used for cutting, has a straight blade and is mainly intended for making entry holes into materials like drywall, but it isn't designed for the flexible, curved cuts that the coping saw excels at. The hacksaw, primarily used for cutting metal or plastic, features a different blade and frame configuration, making it unsuitable for the kinds of detailed work that a coping saw is designed for. Thus, the coping saw is the ideal tool when precision in crooked or curved cuts is required.