Radbug

 Radbug are versions of the regular bugs mutated by radiation.

They have an orb-like main body with a small head and six limbs with a claw on the end of each. When attacking, they leaps towards and claw or bite a targeted creature - dodge quickly to avoid these pests, as they are very mobile. They apparenly have a set of human-like teeth and two fish-like eyes. Another strange fact is that they also have an appendage somewhat resembling a tail.

These critters are known to roam the wastes, many of them could be found in such radioactive place like Carbon Crater, Secret Vault Warehouse and the Secret Vault, where the majority of them could be found.

Mini Radbug
This version exactly resembles the standard version of Radbug, but extremely small. Its damage is very low and requires a single shot to be killed. They often attack in groups of 5 to 10 for confuse the enemy due to their size and their speed.

Small Radbug
Similar to Radbug but smaller. A little stronger than the Mini Radbug but slower.

Radbug
These are most common of them. They are roughly the same size as a dog and are stronger than their earlier version.

Big Radbug
These are bigger versions of the standard Radbug, being the same size as Brahmin. These pests are found near their home, in Vault-Tec Warehouse, guarding the Secret Vault and participating in battles between the Super Mutants and the Church of the Lost. They are fairly resistant and attack causes a lot of damage.

Mini Mutant Radbug
A Radbug mutated by the special version of FEV in Secret Vault. These Radbug have a sort of web and spikes generated around their limbs and body and, more important, are protected by a green exoskeleton shell. It's like mini Radbug but does the same damage that Radbug and is hard to kill. It appears five Mini Mutant Radbug whenever a Big Mutant Radbug is killed.

Mutant Radbug
A Radbug mutated by the special version of FEV in Secret Vault. These Radbug have a sort of web and spikes generated around their limbs and body and, more important, are protected by a green exoskeleton shell. They are the same size as a Radbug. They are very durable and do considerable damage, they can kill their targets in 4 or 5 shots even though protected.

Big Mutant Radbug
A Radbug mutated by the special version of FEV in Secret Vault. These Radbug have a sort of web and spikes generated around their limbs and body and, more important, are protected by a green exoskeleton shell. They are the same size as a Big Radbug. They are extremely durable and whenever a Big Mutant Radbug is killed, five Mini Mutant Radbug appear. They do a little more damage than the Mutant Radbug.

Appearances
All Radbugs appear only in Fallout: Brotherhood of Steel.