multiplying centipede

The beam, no bigger around than a couple of my fingers, sliced the creature in half as neatly and simply as if I’d used a paper cutter the size of a semi trailer.
It shrieked in pain, a brazen, bellowing sound that conveyed, even from such an alien thing, the depth of its physical agony. Its hindquarters just kept right on rolling forward, as if they hadn’t noticed that the head was gone. The front half of the thing began to veer and waver wildly, its limited brain perhaps overloaded by the effort of sending nerve impulses to bits of its anatomy that no longer existed. It settled into a pattern of chasing its own retreating midsection, rolling in a great circle that crushed the ranks of primroses on either side of the trail.
“Booya!” I shouted in pure triumph, the adrenaline turning my manly baritone into a rather terrified-sounding shriek. “What have you got for fiery beam of death, huh? You got nothing for fiery beam of death! Might as well go back to Atari, bug-boy, ’cause you don’t got game enough for me!”
It took me five or ten seconds to realize what was happening.
The wound I’d inflicted hadn’t allowed for much bleeding, cauterizing even as it sliced—but even that little bit of bleeding stopped on both severed halves of the monster. The front half’s wounded rear end suddenly rounded out. The second half’s wounded front end shuddered and suddenly warped in place, and then with a wriggling motion, a new head began to writhe free of the severed stump.
Within seconds, both halves had focused on me, and then two of the freaking things rolled at me, jaws clashing and snapping, equally strong, equally as deadly as before. Only they were going to come rushing at me from multiple directions now.
“Wow,” Bob said, in a perfectly calm, matter-of-fact, conversational tone. “That is incredibly unfair.”

Changes Chapter 12 Page, 107-108