What vegetable is cool, but not that cool?

What's the difference between a hippo and a Zippo? One is really heavy, and the other is...

I am a canine who can be found at certain minor league baseball parks, retrieving a hitter’s wooden implement. My title suggests I could be a pet for Adam West or Christian Bale.

A piece of paper and a blueberry muffin step into The Napkin Ring, each fighting for their place on the dining table. Announcer: In this corner, weighing zero point one six ounces... The Boston Scrapper! And in this corner, weighing five ounces... The Muffin Man! LADIES AND GENTLEMEN, LET'S GET READY TO...!

I am born from milk but I am not a drink, Left alone with time, I change more than you think. I can be soft or hard, mild or strong in taste, Mice may chase me though that’s a risky haste.