Unlike SIR Units, PEN units can be given to both Irken invaders and normal Irkens. Anj is in charge of PEN production and issues them out mainly to those who she is close to. Like SIRs, they can talk and be reprogrammed, normally obey commands, but can be independent, especially BUNS, one of the earlier issued PEN units. While PEN units are required to protect their masster in whatever way possible, they are not prominently weapons. Their main task is protecting their master, providing necessities, entertaining them, and caring for younger, incapable Irkens like Krom. Most PEN units are feminine programmed with the exception of LoLo. PEN units can be prgorammed as dual PEN-SIR units for Irken Invaders like Myu.
Known PEN Units
- BUNS is Invader Myu's SIR-PEN unit. She is independent and sarcastic, possibly defective. Her name stands for Bodyguard from Unkind New Species. BUNS helps with missions, but mainly hangs around, "defending" Myu. She was likely issued to Myu as a prank.
- PEN-E is Anj's PEN and the first successful one programmed. PEN-E is highly helpful and capable. GIR may have a crush on her.
- LoLo is Krom's SIR unit. He is highly sarcastic and powerful, hates his job, and is the only male PEN unit revealed.