Alien swarmers are enemies in Ratchet & Clank and the 2016 re-imagined game. They are small, hostile, blargian frog-like experiments encountered by Ratchet and Clank in the Blarg Tactical Research Station, Nebula G34, and in the Kogor Refinery, Orxon. They are often found alongside alien snappers and toxic crabs.
In the original release, the swarmers appeared twice. Due to a scientist leaving the cages open, they were found wandering throughout the Blarg Tactical Research Station in "Explore the space station" (during which they were also summoned by an Alien Queen), throughout the nearby warship in "Explore the blarg warship", and outside the airlock in "Journey outside the airlock". Later, they were encountered by Clank again as he explored the Kogor Refinery on Orxon, during the missions "Search the laboratories" and "Traverse the wilderness".
In the re-imagined release, alien swarmers appeared in different locations. They appeared again in the Blarg Tactical Research Station, Nebula G34, throughout the station in "Find the top secret Blarg research project", during the fight against the blargian snagglebeast in "Defeat the Blargian Snagglebeast", and outside as Clank in "Journey outside the airlock". They later appeared in the outer areas of the Blarg Research Outpost on Gaspar, around telepathopus brains, during the mission "Trade 10 brains for a jetpack", and onwards. Finally, the alien swarmers were found in the Deplanetizer, seen in the demonstration for the "Kill Intruders" button in the beginning of "Locate the Gravity Stabilizer", warning Ratchet not to proceed without a Hologuise.
Alien swarmers are small, frog-like aliens with brownish skin, dark brown spots, and black spikes (green with darker green spikes in the re-imagined appearance), which move on their larger hind legs with their smaller front legs for balance. They are capable of sticking to walls and surviving in inhospitable environments. They typically swarm in large numbers, often around either alien snappers or toxic crabs, and will leap forward when biting. On some occasions, they are hidden in fake crates.
In the original release, alien swarmers will zig-zag somewhat in their movement towards Ratchet, though upon approaching, will leap forward to bite in close range, though at a further range than expected. While they are best dealt with using a weapon such as the Pyrocitor and Suck Cannon, they are sometimes better defeated with an OmniWrench, while fire is focused on larger alien snappers or toxic crabs nearby. They can also be lured into forcefields using the Taunter, luring them to their death.
In the re-imagined release, swarmers are even more deadly, as they will charge straight towards Ratchet and attack in large numbers. They are best defeated using an area of effect weapon, such as the Pyrocitor, Proton Drum, Pixelizer, or Mr. Zurkon, to fire at them while taking out the more dangerous enemies nearby.