Random question about yellow anacondas

How long does it take them to reach adult size? I heard anacondas grow very slowly.

They can grow slow, they can grow fast. Depends on locality/genetics, depends on feeding and temperatures. I've seen yellows max out around 7 feet, I've seen them closer to 14 feet. With a healthy feeding schedule you're probably looking at around 2-4 feet per year for their first 2-3 years then they'll slow down a bit and be adult size by year 4-5 where you'll likely stop noticing much growth.