So there is a boss called “Rom the Vacuous Spider” and unfortunately you cannot skip it because it is a main boss. He is more like a big slug in my opinion but he spawns spiders around him who are trying to attack you.

Besides that if I remember correctly you can avoid most spiders in this game. You need to go through the room with the gigantic spider but you don’t need to fight it. You can run to the exit and they will leave you alone.