Haiku 207

Doorbell.
The frosted pane.
A monster waits.

Slimy Sid

In a pond where I played as a kid,
there lurked a monster, Slimy Sid.
Once, a tell-tale bubble rose
from stinking depths. My young heart froze.

Well, the pond has long since dried.
There’s nowhere left for Sid to hide:
One childhood myth that turned to rubble…
but what did cause that awful bubble?