Wiktionary
morning person
n. (context idiomatic English) A person whose who wake up without difficulty early each morning and who is alert and active during the first part of the day.
Usage examples of "morning person".
I'm not a morning person, and hunger never improves my disposition.
I, however, am a morning person, up and cheerful at practically the crack of dawn.
I'm usually a morning person, but after traveling all night, I swear, I couldn't wake up today.
Audrey, no more of a morning person than I, lumbered down from the bathroom where her morning ablutions had taken an inordinately long time.