In Jojo's Bizarre Adventure, Dio's bird with a Stand, Pet Shop, wasn't one of a kind, and its parrot counterpart is even more horrific.
The Jojo's Bizarre Adventure spinoff known as Crazy Diamond's Demonic Heartbreak just gave its first glimpse at who is likely the manga's main villain, but it's the terrifying new stand of this man's lost parrot that's had everyone talking.
The premise of Demonic Heartbreak was first thought to be a bit silly, since it was set to star the sympathetic part 3 villain Hol Horse and a young Josuke Higashikata, the protagonist of part 4. The idea of putting these two very different characters with a comedic bent together had some expecting a more jovial tone, but the series' first few chapters have been anything but. With a heavy focus on PTSD, stress, and trauma's effects on Dio's former minions, the manga has been quite serious overall, exploring an era of Jojo continuity with a lot of potential that's barely been touched.
Hol Horse was initially sent to Japan to retrieve a missing parrot, which was said to be the counterpart to Dio's falcon, Pet Shop. The idea of Dio owning a pet has always been a bit odd, given how little value he placed on even human life, but Pet Shop turned out to wield a Stand. The missing parrot was trained alongside Pet Shop by the same trainer and was also believed to have a Stand, although no one knew for sure. As it turns out, the parrot (known as Pet Sounds, named for a Beach Boys album) possesses a truly insidious Stand, capable of forcing its victims to physically reenact events it witnessed, which for Hol Horse meant his failed attempt at turning on Dio. For a man already struggling with his past, it's pretty much the worst opponent he could hope to go up against. Pet Sounds also watched much of the final battle with Dio in Egypt, and has used other events from that battle on passersbys as attacks on Hol Horse.
Animals with Stands have been a fairly consistent part of Jojo since the concept began, with monkeys, rats, birds, dogs, and cats all having used them at some point. In many cases, they've turned out to be deadly opponents, as they don't think and strategize like a human opponent does; the aforementioned rats very nearly killed Jotaro and Josuke. Pet Sounds adds another layer of complexity to this because, as a parrot, it should be capable of speech and has a human ally. On its own, Pet Sounds might not understand well enough to use particular memories against Hol Horse, but with someone guiding it, the Stand is effectively weaponized PTSD.
Such a match seems quite lopsided in favor of the bird, at least as things stand now, but Josuke's role in the story hasn't quite become clear yet. It's possible that Josuke may act as Hol Horse's anchor to the present (a technique called grounding), helping to shake him out of these memories and keep his mind focused on the battle at hand. Even a Josuke who's inexperienced with his Stand can do that, which would be a very different sort of a role for a Joestar to play in Jojo's Bizarre Adventure.
