Protist Kingdom. The Protist Kingdom consists of mostly unicellular organisms that can have characteristics similar to plants, animals or fungi. Characteristics of Protists: mostly unicellular, few multicellular, eukaryotic, can be heterotrophic or autotrophic. Ex: algae, Paramecium, kelp (multicellular).  .lant Kingdom. The Plant Kingdom is made up of organisms that can perform photosynthesis to make food. Characteristics of the Plant Kingdom: multicellular, eukaryotic, autotrophic, and mostly green in color.