no expert on the astral, but i believe so. most things that are legendary creatures in the physical are really astral beings. don't quote me though, just from what gathered seem to point to that conclusion.
I have made this post in the past for a lesson's input, but I think that it is relevant for here as well.
Yes, this is very normal to see an object like a unicorn while performing astral projection.
While performing astral projection we basically see what we have in our minds and subconscious. If you saw unicorns while performing astral projecting, it simply means that it was what you were having in your mind / subconscious and because of this it appeared in the astral realm while you were travelling. As hecate said very well, thoughts are manifested in the astral realm while astral projecting.
The astral environment is thought and feeling sensitive, so if you feel afraid you will attract fearful experiences, if you feel positive you will attract positive experiences. Your thoughts will present themselves before your eyes so it's wise to pay attention to what you have in your mind and not let your thoughts run wild. If you are attempting astral projection be aware of your state of mind, it should not be practised if you are depressed or frightened of what you may find. Like attracts like in the astral.
As I said, it works with thoughts, positive and negative energy, etc as well. Same thing happens with many other things such as: fear, bad thoughts and negative energy. Also with any randomal thoughts you have in your mind. We mostly see in the astral realm things we are afraid of and attract negative entities because we think about them, and in order to make the dissapear we simply stop thinking about them while astral travelling, and by this we stop attracting negative energies and thoughts in the astral plane so they dissapear from our sight. Also we attract what we see at the moment we astral project, immediately.
For example, if i perform astral projection while i am full of negative energies - i might attract negative entities and sights in the astral realms. For another example, if I think about my fears and about my problems, I will see them in the astral realm. So you if you think about something associated withunicorns, which are very " normal " and a logical for something that you might see in the astral realm.
You might also see in the astral many things that might be questionable, so do not get afraid since this is totally a natural thing that happens in the astral realms. There is nothing to wonder about it, in this subject.
In your case , if you think about what you call " unicorns " ,you will probably see it as what you think it looks like and acts like. We basically get to see what we expected to see, thus we build our own realm when it comes to astral projection. Many people experience and see different things while doing this. That is simply how it works.
This all can be defined as " the law of attraction " and astral realm building by our brains attribute. which is always associated with astral projecting and any forms of other dreaming in general. To sum it up, the law of attraction says that by focusing on specific thoughts, we can bring results. In the astral it can be positive, negative, or just something that you're thinking about. Our minds attribute is to visualize what we think of, when it comes to the astral we attract it.
However, not everything is real, even in the astral realms. The human mind has its own limitation as well, which come intro role while performing astral projection.