The Sanskrit word is "shva-paka" - were they the alleged result of caste-mixing?
What is their background?
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Sign up to join this communityYes, there's a mixed caste called "śvapāka" which is mentioned in the Manusmriti 10.19:
क्षत्तुर्जातस्तथोग्रायां श्वपाक इति कीर्त्यते । वैदेहकेन त्वम्बष्ठ्यामुत्पन्नो वेण उच्यते ॥ १९ ॥
kṣatturjātastathogrāyāṃ śvapāka iti kīrtyate | vaidehakena tvambaṣṭhyāmutpanno veṇa ucyate || 19 ||
One born from the ‘Kṣattṛ’ on the ‘Ugrā’ woman is called ‘Śvapāka;’ and one begotten by the ‘Vaideha’ on the ‘Ambaṣṭha’ woman is called ‘Veṇa.’—(19)
The same is pointed by Baudhāyana:
An Ugra (begets) on a female of the Kṣattṛ caste a Śvapāka. (Baudhāyana Dharmasūtra, Praśna I, Adhyāya 9, Kaṇḍikā 17)
By the way, Kṣattṛ and Ugrā themselves are mixed castes. A Kṣattṛ is a product of a Shudra man and Kshatriya woman while an Ugrā is born from a Kshatriya man and a Vaishya woman. Śvapākas have historically being regarded as untouchables.
As far as a caste being termed as "dog-cookers", I'm not sure whether or not Śvapākas were labelled as such. However, according to A.C. Bhaktivedanta Swami Prabhupada, the "Caṇḍāla" caste is known historically to be the ones to have had partaken dog meat:
To receive the Lord Śrī Kṛṣṇa there were all grades of population, beginning from Vasudeva, Ugrasena and Gargamuni — the father, grandfather and teacher — down to the prostitutes and caṇḍālas, who are accustomed to eat dogs...(Purport to Srimad Bhagavatam 1.11.22)