Jabunga
A Jabunga is a beast that won't let you off easy, even if you beg, cry, or throw your shoes.
My dog is a Jabunga. He barked at me until I gave him a treat.
My gym teacher is a Jabunga. He made me run laps even though I had a sprained ankle.
My friend's dad is a Jabunga. He made my friend eat a whole pizza for missing a test.