Stray Demon

The  is an optional boss found by returning to the Undead Asylum.

The Stray Demon is similar to the Asylum Demon from the game tutorial, but is far more powerful. Among other things, it is no longer susceptible to Black Firebombs.

The Stray Demon can be fought by falling through the floor in the middle of the room of the Asylum Demon, but only after returning to the Asylum later in the game.

Strategy
The player will first fall through the floor, lose some health from the landing, and end up across the room in front of the Stray Demon. Casting Fall Control before the fight will negate the damage players suffer from falling into the Stray Demon's pit.

As much of the fight as possible should be spent at a distance of a few feet behind the demon, because his area of effect attacks are usually triggered and can only reach behind him a short distance. Players can avoid this by walking backwards behind the Stray Demon for 1-2 seconds. In between his explosion attacks, players should pelt his backside with their attack of choice.

The demon will occasionally fly into the air and perform a rear-drop. When this occurs, this can be avoided by walking about two meters away. Using a shield will deal heavy stamina damage. Sticking to his right may damage and knockdown the player due to the weapon facing in that direction.

His second, commonly-used hammer swing explosion is triggered when the player is not behind the Stray Demon and is close enough. It creates a very large, long and very wide hitbox of magic damage. Using a shield is only ever useful if the player faces the center, where the attack explodes from.

There is no place to use the White Sign Soapstone in this area so it is not possible to summon others for this fight.

The Stray Demon is susceptible to bleed damage and can be inflicted with both Toxic and Poison.

Double Hammer Swing
Two horizontal swings of the Demon's hammer. Similar to the Asylum Demon's attack. Can be blocked, but heavy stamina drain occurs. Can also be rolled under, allowing the player to attack the Demon.

Power Smash
An overhead hammer smash. Can be avoided by dodging to the left or right.

Double Power Smash
Can only be used after the first Power Smash. The Stray Demon raises its hammer, then smashes it down again. Can be dodged by rolling to the left or right.

Butt Slam
The Stray Demon flies up, pauses momentarily, then falls to the ground.

Flame Explosion
The Stray Demon swings its arm outwards, then causes a massive explosion in front of it. Unlike the Hammer Drive attack, it doesn't have any backwards hitbox and can be dodged by getting behind, or even under, the demon. Despite the attacks name, it deals purely Magic damage.

Hammer  Explosion
Similar to the Asylum Demon's attack, however, once the hammer hits the ground, a massive explosion occurs at the point of impact. Telegraphed well by the Stray Demon raising its hammer, and can be dodged.

Trivia

 * When first exiting the prison cell at the beginning of the game, the Stray Demon can be seen wandering around his boss arena through the bars to the right, although he can't be reached at this point in the game.
 * The Titanite Slab sometimes will not drop.
 * The Stray Demon shares the same battle theme as the Iron Golem.