All felines. They are my religion. But if I had to choose one, it would undoubtedly be the black panther.
But of course I love my 3 cats more. Every night they come and sleep with me, and they meow to make a place for them so the can snuggle up next to me
To go through the tall grass you have to walk, you can't use the bike.
Iirc, you can't go though that cave yet, and if I'm not wrong, it connects with Byxbysion Wasteland.
Then, you just have to circle the structure from right to left (starting and ending from you read the hint) without detaching yourself from the wall of the same structure, and when you do that, it will say something like "the Old Doll is reacting to something".
Ahh that's beacause you need an special item you can find thanks to one of the Ranger's quests. A ranger will give you a key to access a room full of graves in Weeping Depths. You have to interact with one of them (I don't remember which one) and an entrance will open. In that cave you will find that item.
I think I'm not fogetting anything.