Answer:
Small edible creature from the sea that is often served at restaurants.
It can be white or blue or black, Humped or have a horn. And when it talks it sings its menuets, as it's travelling the depths.
A close relative of ketchup that people often spread on their dog.
What follows a dog wherever it goes?
Oh how I love my dancing feet! They stay together - oh so neat. And when I want to walk a line, They all stay together and do double time. I count them up, ten times or more, And race on-off, across the floor.
What is always coming but never arrives?