Good Bit of the "Surprised-They-Got-Away-With-It-Variety":
SHAGGY (upon first seeing the brush monster through the soapy waters): "Zoinks! It's The Clean Fiend! Like, it SUDS to be us!"
New story.
This story has been reprinted twice within the span of seven issues, in Scooby-Doo, Where Are You? (DC, 2010 series) #80 (June 2017), #86 (December 2017).