Batrat
From A KoL Wiki

This is a hideous amalgam of bat and rat. It seems to be more bat than rat.
It lets loose a high-pitched squeak. Fortunately, you've built up your immunity by listening to Mariah Carey.
It flaps up and munches on your face. Eek! Eek!
It lets loose a high-pitched squeak. You feel a sharp pain in your thigh. Ugh! Ow!
You hit for 15 damage. KAPOW! BOOF! BOOF!
You win the fight!
You acquire an item: bat guano
You acquire an item: batgut
You gain 4 Roguishness.
Occurs at Batrat and Ratbat Burrow.