Pushpaka Brahmins are a part of the Ambalavasi community in Kerala. They carry out the various activities of the temple, including actual priestly activities. Pushpakas lived on the income of the temple and were under its care. There are many sub-castes within Pushpakas, including the Nambeesans and Pupallis.
References
Pushpaka Brahmin Wikipedia(Text) CC BY-SA