Elden Ring's friendly dog actually wants to rip you to shreds
Doggone!
A minor theme in FromSoftware's peerless Soulsborne games is the occasional appearance of an enemy that, for whatever reason, doesn't aggro on you. My favourite example of this is a mass of crows in Bloodborne's Hemwick Charnel Lane, all of which bar one will attack, while the remaining crow just sits there all dopey-like. In a world where everything's out to eviscerate you, something not attacking almost makes it seem like a friend.
The Elden Ring equivalent of this is a dog in Leyndell, which is found next to another enemy, the Leonine Misbegotten. When the player approaches, the latter enemy will trigger as usual and the fight is on: but the dog doesn't move. It just sits there watching on (unless you attack it, in which case it will defend itself).
It adds an especially piquant touch that it's a dog, because in the Souls games dogs are such irredeemable bastards, but the effect is to create a mini-mystery. Why is this dog, of all the dogs, friendly?
Well, turns out it's not. Longtime FromSoft content creator and data-miner Zullie the Witch has been doing some digging, assisted by thefifthmatt, and discovered that every Tarnished's favourite doggo is not necessarily intended to be so friendly. Turns out it has all the usual triggers that would usually see it first react to the player's presence and then attack… but it doesn't.
As the video explains, Elden Ring's enemies enter their aggro state based on player location: when you enter certain zones near particular enemies, that triggers an animation which essentially wakes them up, after which their AI takes over and starts attacking you. In the case of this dog, however, the player entering a particular zone outside Leyndell Colosseum when en route to its location soft-locks the dog into a repeating animation, which is what leaves it as docile as a lamb.
A possible explanation for this is a Gray Warden enemy that was once placed in the zone that soft-locks the dog, but was removed by the final version of the game. Why this should affect the dog's functioning is one of those game dev mysteries, but it's clear that the zone itself it's what's causing the behaviour: should a player never pass through the zone, then the dog is not soft-locked and will attack alongside the Leonine Misbegotten.
This is in all likelihood a glitch but, as Zullie herself mentions, the consequence is to create a little mystique around what would otherwise be just another enemy encounter. It's funny but I played Bloodborne so much I ended up loving that non-aggressive crow and would toss it a few gifts on occasion after killing all its mates. In Dark Souls 3 there's a crab in the otherwise-nightmarish Smouldering Lake that's just chilling, and has clearly stuck in the mind.
Who knows: the Leyndell dog may well be bugged, and desperate to rip you to shreds if it wasn't for this damn soft-lock. Or this may be one of the little Easter Eggs that FromSoft allows itself, an unexpected temporary respite with the hint of comradeship, and the kind of touch that makes these worlds so memorable.