While wearing this amulet, as an action you can create a "Spike Growth" that moves with you. It eminates 10ft from the square(s) you occupy, no matter your size. It has "Proficiency" charges per day.

The ground for 10-foot out from the square you occupy, sprouts hard spikes and thorns. The area becomes difficult terrain for the duration. When a creature moves into or within the area, it takes 2d4 piercing damage for every 5 feet it travels.

The transformation of the ground is camouflaged to look natural, and takes on attributes of the current surroundings.
Any creature that can't see the area at the time the spell is cast, or when it is moved, must make a Wisdom (Perception) check against your spell save DC to recognize the terrain as hazardous before entering it.

For Two Charges it becomes a swarm of flying, biting insects, so the same effect becomes spherical and can be easily seen, (No perception check needed)
For Three Charges it extends into other planes and quasi-planes. It will effect ghosts, ethereal creatures, or creatures in solid surfaces that are within range, etc.

Notes: Has your proficiency number as charges per day, Requires Attunement, Utility, Exploration