Tattler
/ˈtætlə/
noun
One who tattles (notifies authorities of illicit behavior) or is inclined to do so; a tattletale.
“My sister is a big tattler; she always tells Mommy when I hit her!”
Either of two similar bird species in the shorebird genus Heteroscelus (Tringa in some taxonomies).
A device fitted to a vehicle to measure mileage etc.
Synonyms: informant, narc, stool pigeon, tattletale, tachograph