He is a large, buff army green fish with a unibrow, brown hair, and spiky teeth. He wears black pants and a dark blue jacket, and under it is a white shirt. When he is about to strangle someone, his fins turn into fingers. His first name might be "Mac," as Patrick calls him this after sharing a cell together. He wears a fake mustache when he pretends to be SpongeBob's bodyguard.
The Tattletale Strangler is a notorious individual, as even the bravest and toughest fish fear him. He is a pure criminal who has no respect for police officers and will stop at nothing to break the law. He has an irreverent, despicable, and irresponsible attitude, as he rats on his victims for reporting him to the authorities, when they completely have a reason to.
Despite his intimidating demeanor, he has a weakness, which is annoyance at the hands of SpongeBob.
In his next appearances as a background character, he seems to have made amends with the latter and bears no intent to harm him.
"SpongeBob Meets the Strangler"
He is first seen littering on the Krusty Krab property when SpongeBob is on litter patrol. After finding out that he is the one responsible for this, SpongeBob calls the police on the Strangler and succeeds in getting him arrested. However, due to his strength, he manages to escape from his cuffs. The Strangler later disguises his notorious identity using a gag mustache, and SpongeBob, deceived by the disguise, accidentally hires him as his bodyguard.
Afterwards, the Strangler suggests that they hide somewhere private so he can get revenge on SpongeBob, unbeknownst to the latter. After several hours of running errands and attempting to gain entrance to SpongeBob's house, the two finally get inside, but are subsequently interrupted by SpongeBob's on-time party and birthday party, preventing the Strangler from revealing his true identity and intentions.
After the partying ends, the Strangler finally plans to kill SpongeBob, only for Patrick to enter his house. The real Strangler falsely accuses Patrick of being him, leading Patrick to turn himself in. When SpongeBob continuously jabbers about Patrick's alleged criminal status, the Strangler becomes annoyed and eventually gives up to reveal his true identity.
He is no longer intent on harming SpongeBob and actually tries to get himself imprisoned just to be away from SpongeBob, which he eventually accomplishes; however, the Strangler's inmate turns out to be someone just as annoying as SpongeBob: Patrick.