Each answer contains the name of an animal.
1. a cold Christmas swim in here(3,10)
2.Immutability proverb(1,7,6,6,3,5)
3. Really enjoying myself(6,1,5,2,1,4)
4. Fruitless hunt(4,5,5)
1. a cold Christmas swim in here: The Serpentine
2.Immutability proverb: A leopard cannot change its spots
3. Really enjoying myself: Having a whale of a time
4. Fruitless hunt: Wild Goose Chase