The wildlife guide tells you how to attract all the myths. You are attracting the Pegasus until your pink cap is ready for harvest, but you have so much competition I doubt many will show up. You need raised tables with veggies and nothing else competing for the food.
For winged unicorns you need a ready for harvest enchanted pink mushroom or a fully grown higher enchanted mushroom.
It’s all in the wildlife guide if you forget. There are a lot of mushrooms to keep track of! :)

And don’t forget to use raised feeding tables! :)

You don't have a mushroom currently that will attract the winged unicorn. You would need a RFH enchanted pink mushroom, or a fully grown Higher enchanted mushroom to attract one, as per the Wildlife.

You might get a Pegasus with the fully grown Pink Cap, but you have a lot of competition for the veggies - use high tables to reduce that.

Thank you both 😊