She is a cute brown centipede who is based off of a dilemma. The Centipede's Dilemma. There is this one poem that she hates which is written by Katherine Craster which is:

A centipede was happy – quite!
Until a toad in fun
Said, "Pray, which leg moves after which?"
This raised her doubts to such a pitch,
She fell exhausted in the ditch
Not knowing how to run.

This reminds her how she lifts all of those legs individually and it overwhelms her now since all of that was automatic and now manually