One of the first wild animals Alis is likely to encounter when setting out from Camineet is the Sworm, a type of giant fly. And in fact, their stronger, fire breathing cousins were indeed named "Giant Fly." In
Phantasy Star, they attacked head on, content to hover in place during combat. The same creatures would return for
Phantasy Star IV with nearly identical properties but different names. For
Phantasy Star - Deluxe Edition, their visual appearance was altered to give us an overhead view of the monster. Now we can see a claw-like ending on the tail, while the facial expression seems more unfriendly.
Internally, the game refers to the Sworm as "monsterfly," which matches the name used in
Phantasy Star IV.