Hi I'm a developer of this game and I'm sorry to hear that you had trouble finding the combos. We did realize a bit late that we were somewhat to enthousiastic with thinking of ingredients and potions so it did end up a bit overwhelming.
A tip though If you buy a potion from the shop and rewind it there is always one potion combination present and two random ingredients. So if you pay attention to the shelves when you rewind it you'll see what ingredients were inside then you can try different combos of only those and you'll definitely find a recipe.
And when in doubt the "cat" recipe is visible on one of the screenshots of the game on the game page.
Thanks for playing our game and thank you for the feedback.