What type of organism is the grass?

Grass is a Plant from the Eukaryota domain.

Eukaryota is the domain of eukaryotic organisms (or eukaryotes, as they are more commonly known), which have a true nucleus separated from the cytoplasm. And in the cytoplasm there are many organelles. Some classic examples of these representatives (unicellular or multicellular) are: Animals.

It's in the plant kingdom