SEWELLEL
Etymology
Noun
sewellel (plural sewellels)
The mountain beaver (Aplodontia rufa).
Synonyms: boomer, sewellel beaver
Source: Wiktionary
Se*wel"lel, n. Etym: [Of American Indian origin.] (Zoöl.)
Definition: A peculiar gregarious burrowing rodent (Haplodon rufus), native
of the coast region of the Northwestern United States. It somewhat
resembles a muskrat or marmot, but has only a rudimentary tail. Its
head is broad, its eyes are small and its fur is brownish above, gray
beneath. It constitutes the family Haplodontidæ. Called also boomer,
showt'l, and mountain beaver.
Source: Webster’s Unabridged Dictionary 1913 Edition