The Dead Pet, an incorporeal companion...

Was on a run this morning when this song came up on the random feed on my player:

I'm Alive (That Was The Day My Dead Pet Returned To Save My Life)

Mr. Cooper and his spiritual companion animal inspired a bit of magical/divine goodness...

Perhaps you had a stalwart war dog, well trained and fearsome; or a dungeon terrier, bane to vermin and quick to alert you of creeping foes; or maybe just a loyal hound, who followed you off the farm as you left to seek adventure.  In any case, they were a good dog.

But adventuring is as hard on dogs as men, and they met their eventual demise.

However, old Bowser went to heaven (as all dogs allegedly do) and put in a good word for you.  The Canine Gods heard this, saw that you had been a fair and kind owner and smiled upon you.

Dead Pet
An incorporeal canine, the spirit of an old adventuring companion, follows their former owner for a period of one year (+1 year per charisma bonus).  The original animal must be mundane, and may not have been a summoned creature, such as a magic user's familiar, or druid's animal companion.

The Dead Pet is invisible and generally goes unnoticed, even by its owner.  However, once per day, the Dead Pet may provide aid or interpose itself between the former owner and danger in one of the following three ways:

Source

"So I couldn't see the truck
That was sixty times my size
And just seconds off from splattering me
Let me tell you
I was so scared I couldn't move
Like my boots were full of glue
Then I felt a little tug
And I thought of good Old Blue
And he pulled me from that catastrophe"

The Dead Pet dispels a fear-based effect by monsters or spells targeting the former owner.  Paralysis saves are made at +2.

"I was spitting in the canyon
Near the cliff up on the mountain
When an unexpected sneeze
Hung me in the breeze
At forty five degrees in the sky
Suddenly I felt something
Had me by the belt
And in between my praying
Swore I heard a stallion neighing
Was the ghost of my horse"

The Dead Pet may either: 1) warn the owner of an imminent physical danger (such as a collapsing tunnel or pit trap), or 2) interpose itself between a physical danger and the owner, negating any potential damage (such as a crossbow or blade trap).  (At the DM's discretion, the Dead Pet may also be a horse, particularly the paladin's warhorse).

"Things were getting gory
Got caught on territory
Belonging to the Crutches
In an alley in their clutches
Looking kind of dismal that night
Well the leader's name was Fats
Swinging broken baseball bats
Things got really frantic
Starting jumping in their panic
Hallucinating billions of rats
Lots of rats"

When the former owner is outnumbered by foes and has taken damage, the Dead Pet may manifest itself as either a fearsome countenance or as a swarm of vermin.  This will have the effect of a Scare spell (85%) or Fear spell (15%).

During the period that the PC is accompanied by their Dead Pet, they may not take on any other animal companions or familiars (mounts excepted).  The Dead Pet has incorporeal qualities, and may be turned by an opposing cleric as the equivalent of a 4HD undead.  If turned or otherwise dispelled, the Dead Pet will return the following day.  At the end of the Dead Pet's service, the former owner will sense a ghostly dog brush past them and find a small carved dog by their foot.