Hi! So, I’m relatively new to this whole thing, and I’ve only been on my own journey for about 8 months, though my mom has been at this for a long, long time.
My mom and I have been seeing this... thing around the house. My stepfather was the first to see it, it’s dark, with no defined face aside from big yellowish eyes, and short/spiked dark tentacles. The first time he saw it it seemed.. shocked that he could see it, quickly went away, but circled back and looked at him again. He doesn’t think he looked anything like any astral parasite.
Also something to note, my small coven and I have recently encountered a spirit we don’t know all that much about, but from what we’ve gathered, there wouldn’t be any kind of connection between the two.

Reminds me of an octopus humanoid that is more in its octopus form.. just a general assumption though. Have you asked the rest of your keep what it might be? They would have more knowledge than you regarding the supernatural entities around the house, if it indeed is supernatural.

Sounds like your family, you, your mom, and dad are experienced and been dabbling in spiritually. Are you sure asking about this here is a good choice? As I'm sure you guys have your own believe and answers here might clashing with it.

But to start with, as the rules, no smoke without fire. It might be a good start to think back what you were doing before related to that 'thing'.

Maybe the issue is what do you want to do about it?

If you want to keep malicious, uninvited spirits or entities away, you could try banishing and getting protection.

This link is to a free banishing and protection ritual and cleansing method.
https://www.creepyhollows.com/faq/index ... artlang=en

These can be bought cheaply from the Creepy Hollows Shop.
https://shop.creepyhollows.com/COPPER-R ... IRITS.html

There are many more layers of protection that can be added. For example, a spirit or spell binding for home protection or as a personal companion protector. And so on.

More sophisticated things that banish and protect are available from the CH Shop if you want them.

I agree with CJDS comment actually.. It does feel like you and your parents have gifted sight and probably have their own practices or methods of dealing with these things maybe. Kind of interesting they can all see it, I have to say.
It sounds like it might be some type of entity maybe... that is watching you perhaps?
I'm totally making my own thoughts on this but I feel maybe it's not harmful. But if you discern and feel its presence is negative then it might be good to get rid of it.