We are not plants because we can't make our own food using sunlight. We are not animals either because we don't have mouths or stomachs - so we can't eat like humans do. We have to break down our food first and then absorb what we need for growth and development.
The Fungal Kingdom is one of the largest kingdoms of living organisms on our planet because scientists think that there are at least 1,500,000 (1.5 million) of us to be found.