Answer: eagerbeaver

AnswerCrossword Clue
EAGERBEAVER

Go-getter

EAGERBEAVER

Overly diligent sort

EAGERBEAVER

Overzealous one: Slang.

EAGERBEAVER
Ardent rookie.
EAGERBEAVER
Diligent one.
EAGERBEAVEREnthusiast
EAGERBEAVERGung-ho type