Acalā (Achalaa) was a mātṛkā (matrika; lesser female deity) present during the coronation of Skanda-Kārtikeya (Skanda-Kartikeya) as an attendant.

Mahābhārata (Kinjawadekar)(9.46.14)
Mahābhārata Vols. 1-43 (Siddhāntabāgīśa)(See line no 14 of the footnote of verse number 9.42.52. Vol. 29. P. 478)