Mary and Fred are two exceedingly unintelligent aliens of an unknown species who make a living out of capturing and collecting alien specimens. It is important to note that "Mary" and "Fred" are not their real names; rather, they were the names they had written on the name tags of their "human" disguises. Mary speaks with a stereotypical 'hillbilly' accent; she constantly refers to Fred as 'Pa'. Fred, however, speaks with more of a Cockney British accent.
Their species are brownish-green in color, and have solid-colored eyes, similar to an Irken's. They are very tall, and their shoulders go up to their heads.
Mary and Fred travel around in a huge cloaking device-equipped spaceship, abducting both sentient and non-sentient creatures and performing "experiments" on them. However, all of their specimens have easily escaped, save one, who has been "fused" (duct taped) to various items by Mary and Fred and lacks the limbs necessary to leave his containment tube.
On their visit to Earth, they encountered Zim, and claimed to be his new neighbours while their spaceship knocked out Zim's communication field, interrupting his conversation with the Tallest. However, Zim quickly saw through their pitiful disguises and called them out as aliens; Fred quickly resorted to "Plan two", which was to stuff Zim and GIR in a sack, and take them up. Once aboard their spaceship, the aliens stated their intention to perform a "fusion" experiment on Zim, which involved fusing him "to another human being." The exasperated Irken attempted to make them understand that he wasn't human (going so far as to remove his and GIR's disguises), but even obvious facts weren't strong enough to break through their thick skulls.
Eventually, the two abductors decided to carry out the experiment anyway, which turned put to be far more pathetic than it sounded: in actuality, the "human" they had was really a gopher, and all they did was duct-tape it to Zim's head.
Eventually, Zim managed to distract his abductors by directing their attention toward the ceiling, and easily managed to leave the ship with GIR in one of the escape pods; throughout the chase, Mary and Fred's efforts to recover their specimens can only be described as minimal; even when they were standing outside the open hatch to Zim and GIR's pod, they merely pawed at them halfheartedly.As alien abductors, Mary and Fred are ludicrously inept, ignorant and unintelligent; they are very easily fooled, yet place complete faith in their own, horribly incorrect misconceptions. Moreover, they often lament the fact that all of their specimens escape, yet they do absolutely nothing to fix the facts that their containment tubes can be easily opened and exited from the inside, and their ship has absolutely nothing in the way of security.
Mary and Fred seem to have a limited understanding, if any at all, of humans, Earth, and the universe in general. They have not heard of the Irken Empire, as they "don't get that TV no more". Mary seems to have an obsession with fusing things to Fred's juice, as Fred stated: "Look, I'm the captain, and I'm sick of you always fusing things to my juice!".
They both appeared in Jhonen Vasquez's earlier work, Johnny the Homicidal Maniac. They abducted a man and told him to mate with a female of his kind. This female turned out to be a chicken. Later, they abducted Squee.
- Heuuuehuahuauauhuueaoeueyy YEAH! The dog! Explain it!
- Howdy, Squishy! We would like to vomit language in the young man that lives in this shelter unit!
- Oh! Another escape, is it me? Is it me HUH?!
- Aw the juice! JUICE!
- Aw, now the other one's getting away!
- Oh Look at him go.
- They were originally voiced by Eric Trueheart and Paul Greenberg as placeholders. However, takes were done of Brian George and Jim Wise, who were planned to be the actual voices of the two aliens; due to an audio mix-up, their voices weren't included, but Wise and George are still credited as the voice actors in the episode.
- According to Jhonen Vasquez and Steve Ressel in their respective commentaries, the crew originally sought to get Monty Python members John Cleese and Eric Idle to do the voices of the Abductors, when Cleese declined, it was then sought to get Terry Jones. In the end, none of them agreed to contribute.
- As noted above, their real names are unknown. Because of this, some fans have taken to calling them "Blue" and "Green", in reference to their respective eye colors.
- Despite coming from a race capable of interplanetary space travel, Blue and Green are no doubt incredibly stupid. This seems to suggest that the species as a whole isn't exactly as unintelligent as Blue and Green, and they may in fact be in a similar position as Zim, since they could be considered outcasts to their people and were sent far away from their homeworld in an attempt to get rid of them. However, given that they're the only members of their species to ever show up, this is just speculation.
- Because of their incredible stupidity, Blue and Green can't tell different species apart even when it's painfully obvious. Over the course of their one episode, they confuse an Irken for a human, a robot for a dog, a gopher for a human, and a human for a weasel.
- In the series, Blue and Green could walk while in both Squee! and JTHM they used floating chairs to move around as they had lost their legs. This seems to imply that the events of "Abducted" happened before the comics, assuming they share the same continuity.