Swamp monsters are enemies in Up Your Arsenal, encountered in the Nabla Forest on Florana, during the mission "Find the Mysterious Man". They are large, green, worm-like monsters, with black heads, dark red tentacles around their mouths, and three glowing yellow eyes, which attack Ratchet and Clank by spitting poisonous venom at long range after they appear from the water, or by squashing them with their bulk if they come too close to the water's edge.
Swamp monsters are enemies that can deal considerable damage, and are very tough, able to sustain a lot of damage at the time encountered. While they are not mobile, they have long enough range that they still pose a threat. The best weapon against them is the Nitro Launcher, as it is capable of dealing enough damage to defeat them quickly.
- Up Your Arsenal, Ratchet & Clank Up Your Arsenal Official Strategy Guide, p. 19