Power is subjective by its very nature and, to quote Yoda himself, ' size matters not.' Power, like beauty, is in the eye of the beholder and finesse, cunning, and pure evolution can overcome much. Understand that power, in this case, is not merely a measure of physical strength or size. With Star Wars: The Last Jedi poised to introduce even more alien animals into our popular culture, it's only natural to wonder how what is coming stacks up against what came before.
Some of them possess equally strange abilities that make them far more dangerous than they look.
Even ignoring the Extended Universe novels, the plethora of video games, and all of the other miscellaneous media it has inspired, there are many strange animals out there among the stars. The universe of Star Wars is filled with all manner of exotic creatures.