One good three star strategy for Ragnahog level 5 can be seen in the video below.
Little Red is called upon for a big mission once again. Throw him just over the first structure; he’ll impact the right and drop the boulder on the stove, causing massive mayhem. Next lob Matilda over the structure again, activating her egg so that the carcass takes out the snow block supporting the windmill, dropping that whole mess down on the second Red, freeing him. Finally, toss Stella through the snow block holding up the nearest structure and into the debris pile, killing the final pigs and ensuring your three stars. The score in the video is 148450.