Clynex

Clynex, one of the Elder Horrors, was a glowing immobile sentient crystal creature native to Vortis.

When the Animus arrived on Voris, it drained Clynex's energy. Some years later, after the First Doctor defeated the Animus, Clynex revived. It began to hypnotise nearby Menoptera with is light and kill them. The Fourth Doctor destroyed Clynex by exciting his fundamental resonant frequency with his sonic screwdriver, causing it to shatter. (DWM: The Naked Flame)