Help with clues - What is this snake

[Alanrom]

I have a friend who has given me a set of clues to find a snake

all i have is

- From southern Hemisphere

- maximum 39 inches long

- 8 weeks Pregnant

- Lays up to 15 eggs

- Fades in color with age

- Has vertical eyes

Anyone have any idea? It is driving me crazy much to my friends joy!