Or Kalakhanja.

A common name for the group of asuras born to Kashyapa and Kalika as per Mahabharata Adiparva Chapter 65. They are about 60000 in number. They have fought under Vritra and other asuras too.

Once the Kalakeyas started harassing brahmins – killing them, disrupting their yajnas, and so on. The brahmins complained to Agastya, who set out to catch them. They hid in the ocean, but Agastya drank the ocean up. But a few kalakeyas managed to escape to patala as per Mahabharata Vanaparva Chapter 101.

Hiranyapura, near devaloka served as a base for the asuras. The Kalakeyas once attacked the devas along with a group called Nivatakavachas. Indra sent Matali to bring Arjuna to devaloka. Arjuna defeated the asuras and killed many Kalakeyas as per Mahabharata Vanaparva Chapter 172 verse 3.