At the Krusty Krab, SpongeBob gives everybody a description of the worm; he says it is big, scary, pink, and "all wiggly," to which he wiggles to justify his point. It is revealed to speak, although its only vocal is a long "Ouch!"
Sandy says she can easily fight the worm because she wants to get her tail back, and SpongeBob unsuccessfully tries to stop her numerous times on her journey. SpongeBob and Sandy arrive (after seeing a "worm sign") at the mouth of the worm to which they mistake as a giant cave. Sandy enters the mouth and fights with the tongue, which she originally thought was the giant worm. SpongeBob reminds Sandy that it is not the worm, and that it is just its tongue. They are later chased by the worm until they happen to lead the worm off the edge of a cliff where it crushes the newly moved Bikini Bottom.
The Alaskan Bull Worm had only one line in the entire SpongeBob series.
Its acts of destruction include eating signs, buildings, SpongeBob's home, Sandy's tail, a fish's butt (twice), and crushing Bikini Bottom.
It's similar to the Graboids, from the Tremors series, which are also giant worms. The end of the episode, which showed the Alaskan Bull Worm fall off the cliff, also parodied the end of the first Tremors movie.
Although the worm is large in general, there seems to be a slight inconsistency as to how large the worm actually is. When first seen, he is easily distinguished as being about triple or quadruple Sandy's height, however, when chasing SpongeBob and Sandy, he seems to have shrunken considerably. When SpongeBob and Sandy were riding him, the worm seemed to have grown once again. Lastly, he was large enough to land on and crush the entire city. Likewise, at the beginning of the episode, he was small enough to travel through the city to eat buildings.