Willowisps
 

I noticed that the willowisps in Eruds Crossing can be attacked without magic weapons. This is incorrect. In classic you were required to have a magic weapon equiped in order to hit them. The same goes for pets being able to hit them.

All of the willowisps are set to require magical weapons to attack them.

How did you accomplish this?

As far as pets, they become able to hit magical creatures at 12th level I believe.

Unless your pet has a DS in which case you just heal the pet and let the DS do most of the damage till the whisp tries to run.

Killing whisps at such a low level is best accomplished with an earth pet because when rooted they will keep attacking your DS's pet till they die.