Don't Eat the Hoomans

A thrilling and comical adventure from Ged Duncan, the author of the Sydney the Smuggler trilogy. Sister and brother, Caitlin and Dylan, meet two alien dinosaurs, Krobble and Begga. They find they have the task of introducing them to the world. Begga is always hungry for meat (and Hoomans look very tasty), and the humans are terrified!
From the cover:

Krobble lives on the planet Fitbog with his friend, Begga.
He's been looking for intelligent life on another planet, and he thinks he's found it.
He persuades Begga to travel with him to take a look and hopes to make friends and share understanding.
Trouble is, Krobble and Begga look just like earthly dinosaurs. How will the 'Hoomans' react when they meet them? Can Krobble stop the enormous Begga from eating them? And will they accept his offer of peace?