A better general word for describing a person who snitches is simply snitch. Definition 1 is typical. Definition 1.1 can be a little confusing.
stool pigeon
1 A police informer.
1.1 A person acting as a decoy.
Etymology: late 1800s so named from the original use of a pigeon fixed to a stool as a decoy.
What is a stool pigeon?
A better general word for describing a person who snitches is simply snitch. Definition 1 is typical. Definition 1.1 can be a little confusing.