Shakti chalana mudra. Shadow yoga

"Shakti chalana mudra combines bhastrika and surya bhedana pranayamas with the processes of nauli kriya and khechari manthana (churning of the tongue). Woven together these awaken, engage and raise the kundalini shakti (the coiled power of life). This causes the prana-vayu (life breath) to enter the Sushumna Nadi that carries the awakened power in its upward surge."- reference: Shakti-Calana Mudra article by Sundernath