Floating Chrome bubbles/orbs in High Garden

Umm..info pls? Why are they there? Cant kill them they follow and then just disappear after a time....cant seem to find any info anywhere.

Whisper

The bath house and the high gardens (and probably some other zones, not sure if there are more than those two) contain chrome infused mobs, which spawn these floating orbs when you kill them. They inflict a chill debuff if I recall correctly. They might also do some minor damage.