I built a 1,000 gallon pond on my patio about 25 years ago. It took a couple of years for the bullfrogs to find it, but I've had them ever since. Two competing males will be unbelievably loud. Fortunately, the sound doesn't bother me at all, I like it.
The females lay literally thousands of egg in a gelatinous string several meters long. I think they must synthesize that string as they expel it, because there's no way their bodies could contain all that stuff.
My goldfish feast on the tadpoles for half a day, then they all get sick because the tadpoles are mildly poisonous. A few of the goldys die every year, but that's okay, they reproduce freely in the pond. The adult bullfrogs are also poisonous -- my dog and cats won't touch them.
All of that gelatinous egg string stuff also pollutes the pond, spiking the nitrogen level. So, if I notice those strings, I try to pull as much out as possible. I also sieve as many of the tadpoles out as possible. There will be thousands and thousands of them, and they use up all of the oxygen in the water.
But plenty of tadpoles survive. In the fall, I'll run across these amazing tiny baby bullfrogs about the size of a pencil eraser in my gardens.