It's the exact same size and speed. It has a one hit kill like the tarantula and you can kill it in one hit.
You enter the boss chamber and its spawn point is randomized.
The accompanying song is eight minutes long, but you would only know that by looking it up on YouTube.
A second encounter happens later in the game where there's a tarantula and a scorpion.
My god the stress of avoiding those little bastards gives me nightmares. And I don't even lose shit when it gets me.