I figured out how the frog breeding mechanic works and thought I could share it.
Each frog has two genes, and as you breed two frogs the offspring will get a mix of the genes from the parents. Pretty lifelike so far.
The genes comes in two categories, one "element" and one "attribute".
Elements: Leaf, Dirt, Eggplant, Heart, Sunflower
Attributes: None, Striped, Spotted, Surf, Whirl
Some frogs have names that hide the true genes of the frog. "Tiger" for example, is actually a Striped Sunflower Frog, if you would look at the underlying genes.
So, if you e.g. breed a Spotted Leaf Frog with a Striped Dirt Frog, you will at random get one of four possible combinations of spotted/striped and leaf/dirt.
If you want an Eggplant Whirl Frog, you need to breed a Eggplant Something Frog with a Whirl Something Frog, and wait for the 1 in 4 random chance to pop up.
Here is the gene chart:
| None | Striped | Spotted | Surf | Whirl |
Leaf | Leaf Frog | Striped Leaf Frog | Spotted Leaf Frog | Surfer Leaf Frog | HypnoFrog |
Dirt | Dirt Frog | Striped Dirt Frog | Spotted Dirt Frog | Dirtsurfer Frog | Dirtwhirl Frog
|
Eggplant | Eggplant Frog | Striped Eggplant Frog | Spotted Eggplant Frog | Surfer Eggplant Frog | Eggplant Whirl Frog |
Heart | Heart Frog | Striped Heart Frog | Spotted Heart Frog | Heartsurfer Frog | Bullseye Frog |
Sunflower | Sunflower Frog | Tiger Frog | Leopard Frog | Sunsurfer Frog | Whirlyflower Frog |
Green = Common
Orange = Uncommon
Red = Rare
I haven't had time to test this thoroughly yet. If anyone spots any errors I would be grateful if you would let me know.
Since I don't have an English version of the game I have borrowed all the English names from a post by chellwatt98, thanks!