Bud and Lou are the Joker and Harley Quinn's two pet laughing or spotted hyenas. Their names are references to the comedy duo Abbott and Costello. Bud and Lou have appeared in Batman: The Animated Series, The Batman and the comics, but remained unnamed until "Joker's Millions". They are often referred to as "Babies" by Harley Quinn.
In the comic continuity before the New 52 reboot, Bud & Lou were explained to have been taken in by Harley and Joker after raiding the Gotham Zoo. They became extremely loyal and loving to Harley and remained her pets even after her arrest.
At one point in time they were stolen by white-collar criminals who tried to auction them off as exotic animals but Harley with the help of Poison Ivy found them out and destroyed the racket.
Sometime around the "Death of the Family" storyline (although not part of the actual story), Harley Quinn escapes the Joker's attempt to make her "fully realized" by dropping her into a vat of chemicals. However, she is confronted by Bud and Lou, who both have been turned rabid by the Joker to turn them into "pure animal instinct." They both attack Harley, who is forced to kill them, much to her sorrow.
In the 2016 run of Harley Quinn, it is revealed that Harley managed to keep them alive and gave them to a zoo where they both had pups. She also reveal that their full names are "Budsie" and "Louie".
In Krypto the Superdog, both hyenas have red fur with black spots and black rings around their eyes. Bud wears a purple collar, has a black right front paw, and speaks in a higher voice. Lou wears a green collar, has a black left front paw and right hind paw, and speaks in a more gravelly voice. (However, in Batman: The Animated Series they are identical and both wear red collars; in The Batman, they are identical, wear no collars, and are grayish in color.) Both hyenas have a distinctive odor. This was first mentioned by Ace in the episode "The Cat and the Bat". Later on, in the episode "Funny Business", Ace told Krypto he could smell their evil.
Like their master, Bud and Lou love to laugh maniacally and play jokes on their foes. Like the other animal characters on Krypto the Superdog, they also seem to be quite intelligent (a reference to the intelligence of actual hyenas). For instance, in "Bat Hound and the Robin", while stealing pillowcases for The Joker to carry loot in, they deduced that the pillowcases made of one material would be better because pillowcases made from the other fabric would shrink in the wash, meaning less loot could be put in them. Also, The Joker has given the hyenas items to use in combating Bat Hound. At one point in "The Dark Hound Strikes!", Bud pretended to give himself up. When Ace seized Bud's collar in his fangs, he received an electric shock. Bud then announced he had a joy-buzzer collar and laughed. In "Funny Business", the hyenas had a bubble shooter which shot special "giggle bubbles". These bubbles caused Ace to laugh uncontrollably, like a mild version of Joker venom.
In Other Media
Batman: The Animated Series
Bud and Lou appeared in Batman: The Animated Series and The New Batman Adventures numerous times. They appeared to prefer Harley Quinn over The Joker, and when Harley wasn't present The Joker refused to feed them. They were also featured in Batman: Gotham Adventures several times but appeared mostly as brief cameos on covers rather than appearing in the actual story. Harley was able to summon them to protect her by simply screaming "Babies!" and she refused to leave with the Joker when he was planning to nuke Gotham, because Bud and Lou would have been caught in the explosion. It has been speculated by fans that the reason why Bud and Lou prefer Harley in this version is due to spotted hyenas having a matriarchal society, putting Harley above Joker in the hyenas' eyes.
Bud and Lou appear briefly with the Joker on The Batman, but are actually depicted as being more monstrous and disgusting, mangy critters. Unlike their original versions, they were albino, a fact remarked on by the Joker, who said they resembled "their dad". They were sent after Batman, Batgirl and Catwoman on Killgore Steed's private island, but were subdued and befriended by Catwoman, who remarked that hyenas are more closely related to cats than dogs in response to Joker's surprise that a "canine" would be so friendly with her.
Batman: Arkham City
Bud and Lou appear in the game Batman: Arkham City. They are on display in Cyrus Pinkney's Institute of Natural History, which has become Penguin's stronghold in Arkham City. When activating the display, the Penguin's recording says "Recognise Joker's pets? Me too. That's why I had them shot and stuffed!" Scanning the hyenas solves the "Have Joker's pets laughed themselves to death, or just eaten too much?" riddle.
Bud and Lou appear during Harley Quinn's pre-fight cutscenes for Injustice 2. During some opening dialogue, she mentions that she intends to feed her opponent to them. Bud and Lou can be used by Harley as her character trait, calling them to attack her opponent. In her Super Move, Harley summons the hyenas to maul the opponent, though she calls them off after a few seconds.
While not appearing in the film, Harley does adopt a pet hyena who she names Bruce.
Harley Quinn (Series)
Bud and Lou appear as of season 2 as Harley's pets.
- Bud and Lou are named after the renowned comedic duo Bud Abbott and Lou Costello.
- Bud and Lou being the pets of Harley (and Joker) is in-reference not only to much of culture demonizing the animals for many of their more unique and scavenging traits, but also because their communicative sound sounds like laughing. In hyena clans, it is believed that the louder a laugh the higher the rank of the hyena in the society.
- Bud and Lou have personalities similar to those of dogs. In real-life, hyenas are actually feline in anatomy and in behaviour.
- Both Bud and Lou tend to be characterized as male. While there is nothing saying that this cannot be true, in real life female hyenas are larger, more aggressive, stronger and more socially adept than the males.