Snail mucin has numerous skin benefits:

On top of this, Snail Secretion Filtrate contains a variety of vitamins and minerals. These include copper peptides, Vitamin A, and vitamin E. Vitamins A and E are antioxidants. Antioxidants help fight free-radicals that damage skin cells.

Being cruelty-free means a brand does not experiment on animals.
If you're worried about the well-being of the snails, we recommend looking more into the company of the product. Many brands have developed humane methods to collect snail mucin.

There is much debate on this subject. On one hand, this ingredient comes from an animal. On the other hand, many will argue the ingredient is naturally secreted (like a natural by-product) and therefore vegan. If you have reservations, you can look into Galactomyces Ferment Filtrate or Centella Asiatica Extract as alternatives.