Probably most important thing here if you don't know it: You can grab pink lizards with E and even throw them just like green seeds/orbs, and when carried they will open flowers for you like usual.
With it you don't have to rely on their often questionable intelligence early in the game and you can carry them where they wouldn't normally go even when befriended.




They will also hide like this when befriended and you're in the bush.

It's not listed in the control settings but you can walk instead of running everywhere by holding left ctrl for whatever reason.

Pic not related

Their main use is to distract black bear-pinecones, but young ones like to play catch with them. If you throw it at one of them, they will hold it, and when you sing they will throw it back at you.



They will even bounce off pink flowers just like green seeds.

If you manage to bring one close to lizard, it will come, shamelessly steal it from you, and eat it, even if you didn't befriend it.

Surprisingly adult ones don't care about them.





And when you throw it at big bird mom she'll open her beak trying to eat it but her slow reflexes won't let her.

When you sing on young deer's back it will run faster, it doesn't seem work with other rideable animals, even adult deers.

No clue why it's a thing.

In section of the game where Silent ones are stealing water, if you sing to lying fish it will sometimes try to sing back instead of trying to eat you. Doing so will reveal its symbol.
It is even marked on map before The Great Tree but from what I know it's the only time you can actually see it.

Ps:That means if there was big fish mom maybe she could teach Fe their language too, considering she wouldn't be hungry.