Those critters with guts. They come in all shapes and sizes. They, like viruses and bacteria, are all around us. They can be helpful and some can be harmful to us. They aren't plants but they sure do act like plants.
Fungi are different from plants in several ways.
Fungi need already formed foodstuffs. In other words they like to eat what others have made. However, this is good because when plants and animals die someone has to get rid of the remains. Fungi have long thin cells that are very similar thoughout the entire body of the fungus. Plants have many different types of cells that make up different plant parts like leaves, roots, stems, etc.