In this particular text animation designed by Nick Pearson, you will see that the text has an underlying blur to it. This is formed by two different coloured variations on the same text beneath the first layer of the text. When you hover over the text, the other text in the background kind of expands out. So all those effects in combination give this one a distorted effect.
If you are having trouble with the pen, try the archived copy on GitHub
Gliched Text Hover Animation Snippet
See the Pen Text hover effect by Nick Pearson (@nckprsn) on CodePen.0