Related Clues:

• Blob on a slide
• Somewhat, with "a"
• Infesting critter
• Creature on a slide
• 'The Far Side' critter
• "The Far Side" critter
• Microscopic organism with single cell
• Tiny one-celled animal
• The Biblical widow's offering
• Microscopic organism with single changing cell
• Microscopic organism of single cell constantly changing shape
• Very small creature or child
• Tiny one-celled animal in water
• The widow's contribution, just in time
• O, Mam, be a one-celled animal