Skulltula appear very much like their Twilight Princess predecessors. They are spider-like creatures with eight legs whose main attack is to dash its body towards Link.
These monsters can appear in a few different ways. Some just drop down the ceiling, others are hanging from a string, while some have full blown spider webs created to block your path.
How to Defeat
The Skulltulas hanging from a single string can be defeated by performing a horizontal sword slash to spin them around, then slash/thrust their underbelly. You can also break their string using the Beetle etc.
The ones in the middle of a spider web can be defeated by cutting the web around them, so they’re forced onto the ground. If the web is very small, this won’t be possible though–instead, you’ll have to go around and hit them from behind.
Skulltulas on the ground can be defeated by performing a vertical up slash to flip them over. Once they’re upside down, finish them off with a Fatal Blow. Don’t tarry as they can shoot web at you to trap you.