New Geico commercial featuring yet another Looney Tunes character.
Good one with a twist. 
Ren is another who should stay away from Red Bull.
Roger Rabbit
Speedy Gonzales
Speedy Gonzales – and Sonic the Hedgehog – could probably cope. It’d rev them up something amazing – might push Sonic into “Super Sonic” mode – but I don’t think it’d mess them up. Same for the Roadrunner. Super fast becomes Super Super Fast, but he isn’t going to spin out and rear-end a semi. He’ll just find himself in the Sahara or the Australian Outback. (“Come to Tazmania…”)
I dread to think what it might do to Droopy Dog…
The Warner siblings.
Beavis.
Woody Woodpecker.
On the flip side, I’d like to see Elmer Fudd slam six Red Bull and vodkas.
Daffy Duck should never have an energy drink. Along with Droopy, I’d like to see Slowpoke Rodriguez have one, though.
Edward from Cowboy Bebop.
Bucky Katt already seems rather hissy (pun intended) and probably doesn’t need to get any more amped up. Garfield on the the other hand could definitely use some some juice. Or at least a cup of coffee.
Pinkie Pie.
Huckleberry Hound, Snagglepuss, and Elroy Jetson come to mind.
And Pinkie, Oh that would be Not Good!
Scaredy Squirrel?
Katie Ka-boom.
Dash, of The Incredibles.
Why Huck, Snagglepuss, and Elroy? None of those characters are particularly hyperactive.
Donald Duck - with his shitty attitude, the last thing you want to see is him hopped up on goofballs.
Never give Dennis the Menace an energy drink.