You start with your best howl at the moon.
"Gr-r-r-r-ruff! Gr-r-r-r-r-ruff! Rrrrrrrr!"
You pause for a moment.
The moaning has not ceased.
"Ne-e-e-e-e-eigh!" you continue with a horse.
You then try a few pig-like snorts.
"Snort-snort... grunt... SNORT."
You listen for a minute. The moaning seems to have abated.
But no, after a brief pause, the intermittent moaning starts back up again.
What do you want to try next?