Cyndaquil is most likely based on an echidna because of its long nose and the quill-like flames on its back. The fire on its back could also be based on the quills of a porcupine. It’s nose also seems to be like that of a shrew.
It may also be inspired by the Mustelidae/Weasel family. I only say this because Cyndaquil’s evolutions, Quilava and Typhlosion, seem to be based more on Weasels or Wolverines.
Name: cinder + quil