So, what are these things?"
"Mutated viruses from the Korthos Sector.
Zyphoids were mutated viruses from the Korthos Sector which was created by Zyphoid Spawners. The Zyphoids looked like mushrooms, and they had three tentacles. They came in two varieties: small and large. They appeared on Quantos, Zanifar, and Vapedia.
Appearance on Quantos
The Zoni had kept Zyphoids off Quantos for years, but Nefarious's scattering of the Zoni with the Hypersonic Brainwave Scrambler caused the Zyphoids to return. When Ratchet and Qwark crash-landed on Quantos, they met a Fongoid Mother who told them that her three children had been attacked by Zyphoids. While Qwark stayed with the mother, Ratchet saved the three children.
About the third of the size of Ratchet, the small Zyphoids were found in large groups. When three joined together, they could form into a large Zyphoid. They had only one eye. These could attack at a short range by butting Ratchet with their heads. Small groups could be found away from any Zyphoid Spawners and would issue a warning call when danger came too close. Like pyrospinners, they can be killed by being hit only once by a weapon or the Wrench. When you arrive on Zanifar, Zyphoids will posses a different color than on Qauntos.
The large Zyphoids were larger than Ratchet, and when attacked, would split into 3 smaller Zyphoids. The larger Zyphoids had three eyes.These could attack at a longer range because they spit acid. Since they were larger, these Zyphoids would guard the Zyphoid Spawner. They take over 3 hits to be split up. When you arrive on Zanifar, Zyphoids will posses a different color than on Quantos.
The Zyphoid parasites, also known as the Swarmers, were another type of Zyphoid. Unlike other Zyphoids, the Zyhpoid parasites had formed a symbiotic relationship with the War Groks. The Zyphoid parasites lived on the War Groks' backs. The Zyphoid parasites attacked anything which threatened the them by biting and spitting acidic globs while on the back of the War Groks.
Zyphoid Parasites attacked in a manner similar to that of the Cragpoles, rushing in groups in spitting acidic globs to overwhelm Ratchet. If one managed to get in close, they would proceed to bite them. It was best to use to the Constructo Shotgun in order to clear them several of them as once, especially since they only took one hit to defeat.