Gak is a colorful, stretchy substance often used as a toy for children. It is typically made from a combination of glue, water, and a thickening agent, which gives it a unique, gooey texture. Gak can be squished, stretched, and molded into various shapes, making it a fun and engaging sensory experience. Originally popularized in the 1990s by the children's television show Nickelodeon, Gak became a favorite among kids for its playful properties. It is non-toxic and safe for children, although it can be messy and may require supervision during play.