That new employee is really enthusiastic; every morning he comes to work at 6:00 bright-eyed and bushy-tailed.
"bright-eyed and bushy-tailed" は知りませんでしたので辞書を引きます。
Dictionary.com: alertly eager; full of energy and enthusiasm: Get a good night's sleep so you'll be bright-eyed and bushy-tailed in the morning.
Cambridge Advanced Learner's English Dictionary: eager and cheerful: He always leaps out of bed bright-eyed and bushy-tailed.
Cambridge International Dictionary of Idioms: to be full of energy and eager to do things; She was bright-eyed and bushy-tailed the next morning, despite having been up half the night.
"bright-eyed" は分かりますが "bushy-tailed" はキツネの尻尾が浮かんでくるだけでちょっとピンときません。 "bushy-tailed" で調べても "bright-eyed and bushy-tailed" にしかたどり着きません。"bright-eyed and bushy-tailed" で憶える慣用句なのでしょう。