Alvin, Simon and Theodore Are This Animal
Puzzle 19 of Running a Marathon Pack
Question is: Alvin, Simon and Theodore Are This Animal
and the answer is: CHIPMUNK
Word Meaning:
CHIPMUNK — Any of the subtribe Tamiina of small, striped rodents; they are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia.
Definitions from Wiktionary.