Thor are a species of monster that exists within the Bubble Bobble Universe. They are reasonably large creatures that somewhat resemble a hammerhead shark. Their behaviour is quite dangerous, and they are some of the more threatening monsters in the Bubble Bobble Part 2/Bubble Bobble Jr. Usually, they stand in a place that makes them difficult to reach, throwing hammers repeatedly, that kill on impact.
Standing stationary, repeatedly tossing hammers in an arching motion, that kills on impact.