WARNING: The following contains spoilers for Cowboy Bebop, now streaming on Netflix.
In the original Cowboy Bebop anime, Ein is the cute, furry member of the Bebop family with a somewhat tragic backstory. Originally a lab dog that was subjected to illegal experimentation and was about to be sold in the black market by Abdul Hakim, the welsh corgi was adopted by Jet Black and became the beloved companion of Radical Edward. While Ein's origin story and relationship to the Bebop members in the live-action series is the same as the anime, it's also given a horrifying spin.
Ein is introduced in Episode 3 of the live-action series, "Dog Star Swing," as one of the dogs abducted by Abdul Hakim -- same as the anime. However, unlike the anime counterpart, Hakim is not looking to sell Ein in the black market, but rather, he intends to kill him along with many other dogs he stole. The welsh corgi is saved from a grim fate when Jet and Spike Spiegel arrive at the scene, though the same cannot be said of Haki who is killed by police.
After missing out on the bounty on Hakim, Jet settles for keeping Ein and giving him to his daughter, Kimmie, as a birthday gift. While his daughter falls in love with Ein at first sight, his ex-wife Alisa does not let her keep the dog as she cannot afford to pay the taxes to keep him. Jet ends up keeping Ein on the Bebop with Faye Valentine becoming fond of the welsh corgi. Not only does Ein assist her in disabling one of Spike's trackers on his Swordfish when she "borrows it" to relocate her ship, but he even helps her re-enact a bounty she captured for Spike.
It's not until Episode 8 of the live-action series, "Sad Clown A-Go-Go," that Ein's backstory is elaborated upon. In the episode, Vicious -- now fully aware that Spike is alive -- breaks Pierrot Le Fou out of the lab he's imprisoned in to hire him for an assassination job. Also known as "Mad Pierrot," it is learned the man was subjected to illegal experimentation in which he was forced to form a neural link with various canines, inevitably causing him to develop a fear of dogs. One of the dogs he established a neural link with is Ein.
While Ein is himself harmless and doesn't use his hyper-intelligence against any of his human family members, he still proves to be a threat to them when Mad Pierrot discovers he is in Spike's custody, the latter of whom he's hired to kill. Following a failed assassination attempt that left Spike critically injured, Mad Pierrot uses his neural connection to Ein to take control of the dog and spy on the Bebop family. He then uses the dog's eyes to relay a message to Spike which freaks out Faye.
Before going out to dispose of Mad Pierrot, Faye and Jet make the difficult decision to leave Ein behind to remove him as a threat as he could still be used as a weapon against them. While Ein is left to feel sad about being abandoned, he doesn't stay alone for very long as he is later found by Radical Edward, who makes him their companion like in the anime.
All 10 episodes of Cowboy Bebop Season 1 are streaming on Netflix.