Heterolobosea

Heterolobosea or Percolozoa, commonly known as amoebomastigotes, is an enigmatic phylum of protists that includes many amoeboflagellates. Naegleria fowleri, the causative agent of the often fatal disease amoebic meningitis, is the only member of this phylum infectious to humans. Typically, their life cycle alternates between flagellate and amoeboid stages.