Turtleson, Jack

Jack/Tad the tortoise is likely Ollie's best friend, given that he is mostly seen hanging out with him in each episode. However, in every mess that he and Ollie/Boes get into, you can bet that his shell will break apart at least once. In the original Dutch comics and animation, as well as in the Italian version, he is a female turtle.
*In the original Dutch comics, the female turtle is called Dolly.