THE BASIC PRINCIPLES OF RIDDLE

Q: My skin is eco-friendly and slippery, I've 4 legs and webbed feet, I hop on land and swim underwater, I really like bugs and small fish to take in. What am I?Issue: If a doctor provides you with three pills, telling you to choose a person each and every half hour, the quantity of minutes will go from having the 1st tablet to the final pill?can t