Books with title Mortimer's Picnic

Mortimer is going to have a picnic with his best friend, Oggy. He's very excited! Then Mortimer gets a letter—poor Oggy has a bad cold and can't come. Kind Mortimer takes the picnic to Oggy instead. But it's a journey—a hungry crocodile, a wolf and a troll all want to eat the picnic AND Mortimer!