BtVS by Whedon and Mutant Enemy. Nightlife is a 1991 novel by Brian Hodge and Dell Abyss.
Angel was having a long, bad day.
A new drug had infected L. A.
Green and cut with cocaine,
overdoses brought, with immense pain,
shifts to animals bent on melee.
Skullflush was the street name of the drug
shipped in by someone a bit too smug.
Jungle tribes had used it
respecting the spirit
but when abused it had an evil tug.
The worst of this demonic fauna,
his head exchanged for a piranha,
had, stupidly, been killed
while both drugged and gilled
and saw his undeath as nirvana.
Now free from the need for a new hit,
able to transform when he saw fit,
he began to eat souls,
treating ribcages as bowls.
His stomach was a bottomless pit.
By using his teeth and willpower
he bought enough drugs for a shower.
They severed his head...
then the killer was dead...
and Angel a swan for an hour.
With Angel weak, on the bed laid out,
Wesley and Fred went on a stakeout.
As drugs were in fashion,
they'd be party crashin'
once Fred came back with the take-out.
Answering the door was the buyer.
The smart-dressed one was the supplier,
The guard wore, above jeans,
a jacket showing greens
along the words: 'Where there's smoke there's fire.'
The waiting Wesley began to doze,
but snapped to when he heard the door close.
Camera frames were spent
on the two as they went,
the seller stuffing cash in his clothes.
Through the town the two cut a wide swath.
The guard's hands were covered in cloth.
Though sun they'd outlasted
his dark shades contrasted
with an amulet shaped like a moth.
Wesley watched with eyes that were wary,
seeing no bags for them to carry.
A thought brought forth chortles
at them making portals
in the time in each house they'd tarry.
Fred came back to the car with coffee
and six donuts sprinkled with toffee.
"Felt the stereotype."
She gave the lid a wipe
and said: "Careful, your drink's all frothy."
Wesley couldn't say how they did it.
Their clothes were tight with no room to fit
the large bundles of drugs
that those two bulky lugs
must have from what their clients remit.
That night, talking work over dinner,
Fred laid pictures outer to inner.
"It is weird but it's clear,
from what we can see here
that the guard grew taller and thinner."
At home, the shaman had his guard sit
with words to make it inanimate.
He moved the jacket wide
from the pot golem's side,
tore some herb off the chest and smoked it.