true slime molds

Myxogastria/Myxogastrea (myxogastrids, ICZN) or Myxomycetes (ICN) is a class of slime molds that contains 5 orders, 14 families, 62 genera, and 888 species. They are colloquially known as the plasmodial or acellular slime molds.

All Myxogastria species pass through several very different morphologic phases, such as microscopic individual cells, slimy amorphous organisms visible with the naked eye, and conspicuously shaped fruit bodies. Although they are monocellular, in extreme cases they can be up to 1 metre (3 ft 3 in) across and weigh up to 20 kilograms (44 lb).