early bird

1. A person who arises early in the morning.
2. One that arrives or takes place early or before others.

[From the expression "The early bird catches the worm".]

Also, early bird gets the worm. One who arrives first has the best chance for success, as in She's always the first one in line and does well at these auctions--the early bird catches the worm! This proverbial saying, first recorded in English in 1605, is so familiar that it is often shortened to early bird, a term also used in the sense of "early riser", as in You can call me at seven--I'm an early bird, as well as "early diner" (This restaurant has early-bird specials at lower prices).

The noun has 2 meanings:

Meaning #1: a person who arrives early before others do

Meaning #2: a person who gets up very early in the morning