Sergeant Tibbs is a tabby cat who served the old Colonel and helped save the 99 Dalmatian puppies in the Disney film One Hundred & One Dalmatians. He lives on a farm owned by a Major General and so the barnyard animals consider themselves their own army. Sergeant Tibbs is friends with his commanding officer, Colonel and the second in command horse, Captain.
In the film, when Pongo and Perdita's 15 puppies were stolen, they spread the word all over London, barking so all dogs could hear. That did work as the word spread throughout Great Britain and it reached up north in the countryside. A hound called Towser picked up the message and sent it to the colonel. Sergeant Tibbs was awakened to tell the colonel about it. When Colonel deciphered the alert, Tibbs recalled hearing puppies yelping near an old mansion, owned by Cruella De Vil. Tibbs and the colonel went to the mansion and Tibbs was afraid to go in. When he did, he found puppies... 99 of them. When he found Pongo's puppies, Jasper and Horace found him and tried to kill him and Tibbs barely got out of there with his life.
When Cruella arrived at the mansion, Tibbs snuck in again and managed to get the puppies out of the main room. Jasper and Horace realized they were gone and checked the house. Jasper found them all underneath a bed and were chased all around. Tibbs and the puppies were cornered and ready to be struck when Pongo and Perdita barged in and began attacking Jasper and Horace. During the fight, Tibbs and the Colonel got all the puppies out and brought them back to the barn where the 15 puppies were happily reunited with their parents. When Jasper and Horace arrived, Pongo got all the puppies out and thanked Tibbs and the others for their service. To keep the bumbling duo preoccupied, the Colonel tried to scare them off but Tibbs and the Captain were positioned behind them and Tibbs used the Captain's hooves like a torpedo and literally booted them out of the barn.
Tibbs did not appear in the live action film but a cat was seen in the barn who was probably Tibbs. In this version, a stray dog, who witnessed the puppy-napping, helped the colonel rescue the puppies instead.