The Giant Boreworm (Also known as the Great Boreworm) is the second boss of Splatterhouse 3, it is much larger than that of the regular Boreworms and it is assumed that this is the creator of the offspring that attacked Rick in previous games, it stands much taller than normal Boreworms but with a difference in that it has 2 humanoid like legs and no arms.
During the battle, it will laugh mockingly at Rick as it attacks, releasing swarms of offspring that crawl on the floor and latch on to him, after taking a certain amount of damage, the Giant Boreworm's head will explode, revealing a massive amount of miniture Boreworms seeping from its face, it will then get more aggressive until after more attacks it will finally explode, releasing its innards which are more Boreworms which die shortly after.
If this boss is defeated before Jennifer's brain is devoured (roughly around 3:00 left on the timer or more) she will be saved from death, but on the other hand, if the timer falls to 2:00, Jennifer's brain will instead be devoured, leaving her a Mindless shell. If, however, the timer reaches 0:00, Jennifer further mutates into a complete Mindless Beast. In either scenario, you will get a Bad Ending, in which Jennifer dies.