Kala Bhairava Ashtakam is a Sanskrit Ashtakam, written by Adi Sankara. The hymn illustrates the personality of Kala Bhairava of Kashi (also known as Bhairava), the God of Death(Kala). It consists of eight stanzas, characteristic of an Ashtakam.
Kalabhairava ashtakam was written by Adi Shankaracharya. It makes you very strong and powerful. The lyrics will take you close to Shiva and you can feel Shiva when you chant the Hymn. All your issues will be resolved since Kaal (time) will be on your side.