Covered in slime. (Cambridge Dictionary)
If you describe a person or their manner as slimy, you mean that they appear to be friendly but in a way you find unpleasant. (Cambridge Dictionary)
of, relating to, or resembling slime: Viscous. (Merriam – Webster)
Covered by or resembling slime. (Oxford Dictionaries)
Repellently smooth and obsequious. (Oxford Dictionaries)
Slimy substances are thick, wet, and unpleasant. Slimy objects are covered in a slimy substance. (Collins Dictionary)
Something Slimy: Adirondack Algae.
Not so slimy snakes.