Night Howler does not "revert one to their base instincts."

I have seen a lot of Zootopia fanfics and art in which Nick and/or Judy get dosed with Night Howler for real. In such cases they're often stated to "act according to their instincts", and not necessarily the prey drive, which has its' own problems.

But the thing is, that's not how the effects of Night Howler are actually depicted in the movie. Look at how Otterton and Manchas acted after being darted. Snarling, roaring, destructive. Now watch just about any nature documentary. When a predator is hunting they don't growl or roar, they certainly don't walk up slowly with teeth bared and a low grumble issuing from their throat. When an animal, any animal, does that they're giving you a warning, they want you to leave. If an animal wants to eat you, you won't hear it until you either spot it or it comes close enough to strike, then it'll be like greased lightning until it catches you.

Oh, and another thing, you might notice that Manchas only goes after Nick and Judy after they approach him, and Otterton was actually hiding when our heroes found him. That alone should tell you what Night Howler actually does, they're scared. Their inability to tell friend from foe is shut down and they're scared of everyone so they go into "fight-or-flight" mode. Heck, Judy's uncle exhibited the same symptoms as the predators and he was a bunny.

In short, that's what you should be writing about, terrified animals on drugs.

Also, foxes don't have a sex drive outside of mid-winter, their reproductive organs literally shrink.