Headscratchers / Sonic the Hedgehog: Triple Trouble

• Just before the Final Boss, you meet Nack The Weasel, who is just sitting there until he hears Eggman, at which point he freaks out and runs. Why? He seems to be working for Eggman by guarding the Chaos Emeralds, implying he's on his side, so why would be scared?
  • He's not working with anyone except himself. He's a separate threat from Eggman trying to swipe the emeralds for his own monetary gain (he, Knuckles, and Eggman make up the titular 'Triple').