UltraBarbot

The UltraBarbot is an enemy in, being a tougher version of the Barbot.

Wherever Starmen are found, there is a chance of encountering one more more Starmen fighting alongside an UltraBarbot. UltraBarbots can also appear on their own, with an EnergyRobot, or alongside OmegaSaucers. Regardless of what enemies it is paired with, an UltraBarbot is particularly dangerous at any level. It is one of the few enemies capable of using PK Beam γ. This potent PSI attack can instantly kill any party member not equipped with a Franklin Badge.

UltraBarbots are the only enemy type which can drop the rare Plasma Beam, an invaluable item for Lloyd. In the Japanese Famicom version of Mother, this was the only way to obtain a Plasma Beam.

In-game description
"The latest in the product line."

Trivia

 * Barbots and Ultra Barbots appear to be related to Lil Saucers and Omega Saucers. Regular Barbots and Lil Saucers are both robotic silver enemies which can be found in the same areas as each other.  Each of these also has an upgraded red version, Ultra Barbots and OmegaSaucers respectively, which can also be found in the same areas as each other.