This information is found in the Sri Kalyana Sevak Rathotsava Pushpa, 1974 (Pushpam 21 of Sri Kalyana Sevaka Granthamala) of Shri Shankeswara Matha.

This Marathi passage narrates in detail, the daily worship of Malayala Brahman, (the guardian deity of the Matha), under a peepul tree (asvattha tree) in the Advaita Matha at Shankeswar in the Karnataka region and also of a special festival of the deity on Rathasaptami day. But the story part of the passage speaks of Shri Adi Sankaracharya’s meeting a Brahmarakshas during the former’s wide travels and overcoming the Brahmarakshas (Malayala Brahman).

Malayala Brahman, as per the story, on admiring the superb attainments and characteristics of the Acharya, offers to serve him, whereupon He ordains Malayala Brahman to protect the institutions established by him and says that Malayala Brahman will be worshipped by the heads of those institutions.(Sri Vidyaranya, Published by The Vidyaranya Vidyapitha Trust, Hampi, 1983)