Related Clues:

• Pseudopod formers
• Low life?
• Microbes
• One-celled swimmers
• One-celled creatures
• Simple life
• They haven't any definite forms
• Microscopic creatures
• One-celled organisms
• Shape shifters?
• Microscopic shape-shifters
• Protean ones
• They're often under the microscope
• Unicellular swimmers
• Shapeless blobs