Grumblebug

The Grumblebug.

The Grumblebug is a Petpetpet which makes grumbling noises. Petpets which have them get scolded, and if this is because the Grumblebug makes them grumpy or if their Neopet thinks they are grumpy because of the noise isn't explained. The Grumblebug is featured as a Petpet Supplies item called Grumblebug Water Bowl, which said a grumpy Petpet it might like.