Copycat (noun)

1. A person who imitates or mimics another.
2. A product or action that imitates or mimics another.

Origin:

The word "copycat" is a combination of the words "copy" and "cat" that has been in use since the 20th century.

Examples:

1. She accused her colleague of being a copycat, using her ideas without giving credit.
2. The new restaurant is a copycat of the popular one down the street.
3. The copycat version of the product was cheaper, but of much lower quality.
4. The company accused their competitor of being a copycat, using similar design and features.
5. The singer was called a copycat for mimicking the style of another artist.