I found this in Dark Worlds Quarterly Magazine:

The MURDER Bull

The MURDER Bull doesn’t appear in any of Wellman’s stories but is featured in a scary song that John sings in After Dark (1980). The song tells of two cattlemen in Texas who murdered each other in 1884 over an unbranded bull calf. The other cowboys branded the word MURDER on the animal and drove it away. The bull wanders and grows to become “big and terrible”. The last two stanzas of the song explain what happens to those who see the MURDER BULL:

While you sit in there, watching
The fire that dulls and dies,
He’ll come up to the window
With MURDER in his eyes.

Then turn and look the other way
And hold your frightened breath,
For if you face the Murder Bull
His eyes will give you death.”

The Little Black Train

Like the MURDER Bull, another portentous phantom is the Little Black Train, which takes the souls of the damned to Hell.

I heard a voice a warning,
A message from on high,
“Go put your house in order
For thou shalt surely die.

Tell all your friends a long farewell
And get your business right —
The little black train is rolling in
To call for you tonight.

In “The Little Black Train”(F&SF, August 1954) it is Donie Carawan who must worry about the phantom express, for her sins: seducing a lover to kill her husband. Even selling the railroad she inherits cannot stop the Little Black Train for its rails are as unearthly as the train. Robert Bloch used a similar legend in his Hugo winning story “That Hell-Bound Train”(1958).