Simplify the following text for a Grade 5 native English-speaking person.
Original: Published since June 19 , 1978 , it chronicles the life of the title character , the cat Garfield ( named after Davis 's grandfather ) ; his owner , Jon Arbuckle ; and Arbuckle 's dog , Odie .
Simplified: It has the cat Garfield , the dog Odie , and their owner Jon Arbuckle .