Opuntia microdasys var. albispina

An adorable cluster forming cactus and a close relative to the Bunny Ear Cactus. 

How to care for your Cactus -

Water: Water sparingly and allow to dry out in between watering

Light: Prefers medium light conditions.

Humidity: High humidity requirements. Mist frequently and stand in the shower or a tray of water from time to time.

Temperature: Needs average to warm conditions 16-25°C but will be OK down to 10°C for short periods.

Other info - 

Toxic to cats & dogs? No