The Mystery Cartoon Character Game, ongoing-ier.

Sorry, but I can't cure your headache. I checked all the 2003 deaths on Wikipedia, and read some of the bios, but couldn't find the one who played a mouse.

No prob, Em I, the headache's gone (aspirins, fresh air, sit still). Further, I really don't want this to be another stumper, so if three more clues become necessary, I'll include references that'll ice this Mystery Character.

This wouldn't happen to be Roy Knable from "Stay Tuned," would it?

Oh yes it would, FluidGirl; verily it would be Roy Knable. Most of the comedy movie Stay Tuned is live action, about a couch potato husband who signs up for a "special" package of 666 channels. He gets sucked in, literally, to programming meant for Satan. At one point, Roy gets converted into a cartoon mouse, and has to flee for his life from a cartoon robot cat. The late John Ritter played Roy Knable, and Pam Dawber played his wife, Helen. The animation was done by Chuck Jones, who ran his own studio at the time. Good going, FG; collect another +1 for the trophy case, and take control of the board.

I thought it might be that actually--but at the time, there weren't enough clues to verify it--and I was away at work.
While I haven't seen this movie, I've seen the cartoon segment--it's rather cute. "Kids, don't try this at home."

I know, right? It must've been a head-bender-and-a-half for poor Helen, who reminds herself that she's a human mother with two wonderful children, and opens her wallet to view her kids' photos ... and the kids are cartoon mice, too. That'll mess up any mother.

All right, onto what I like to call the Vault of Obscurity . . . . .

1. My show was one of the first to air on the Fox Kids block when the block first premiered

2. For a show that was billed as a comedy series, it sure took a turn into the creepy and supernatural all the time

3. My first name is defined as being stubborn, but I'm not. My last name is the same as a Footloose Hollow Man.

Found it! It's Pighead Bacon, from "Piggsburg Pigs!"

1. It was one of the first shows from Fox Kids, back in 1990.

2. The show often had supernatural themes.

3. "Pigheaded" means stubborn, and Kevin Bacon was in both "Footloose" and "Hollow Man."

I did the same checking and found Piggsburg Pigs, which led me to Pighead Bacon, one of three brothers that defend the family farm from the Wolf brothers. Originally produced by Joe Ruby and Ken Spears, who got their start at Hanna-Barbera, the series was absorbed by Saban Entertainment, which in turn was bought out by the Walt Disney Company. Politics and cartoons make strange bedfellows.

Correct, Em! "Piggsburg Pigs!" was an obsession of mine when I was eight years old, and Pighead was my favorite character from it, and I was thinking about this particular show all week. I doubt it'll ever come to DVD, though. Actually, I'm kind of glad you got it, I didn't think I'd be able to come up with three more clues!

Thanks, Fluidgirl. But truth be told, OUB posted the right answer while I was editing. So officially, the next turn is his.

I saw OUB's post below yours, Em, which made me think you got it first, but if it's OUB's turn, it's OUB's turn, then.

Such laudable integrity and honesty; no wonder I like this forum so much. So, I must find a Mystery Character that also has integrity. Bingo!

1) This character has appeared twice, in two separate series that share a universe. It's like the A New Hope / The Empire Strikes Back / Return of the Jedi, followed by The Phantom Menace / Attack of the Clones / Revenge of the Sith. The second series is a prequel to the first.

2) This is an anime series, both of them. The anime came first, then the comics, then the game, all from late 2012 through 2013 into early 2014.

3) Reluctant Hero might best describe this character, since she (yes, a girl) came to the setting to get away from it all. Fate, however, has other plans. When it's not her friends and associates pleading and cajoling, it's other peers using strong-arm tactics to thrust this character into the leadership role.

And I'd better include one more clue, because there's so many anime series with Reluctant Heroes that there's going to be multiple Correct Answers.

3½) You think girls can be just as competitive as boys in scholastic sports? You ain't seen nuthin' yet!

There are so many anime series from the past three years, that I just couldn't find the right one. Besides, the threat of a blizzard may make it hard for me to play for a few days.

Hmmm. This is going to be hard since I don't watch anime. I'll keep looking though.

I'm not much of an anime fan, so I definitely wouldn't know.

Okay, hint taken. Time to put this Mystery Character squarely in your gunsights.

4) Once upon a time, this character played on a championship team for a prestigious school. However, when she did "the right thing" during a match, it was treated as an egregious dereliction, which took all the fun out of the sport. Thus, this character transfers to a lowly school to escape the stigma of her playing days.

5) They're a tight-knit bunch at the new school. When this character gets bullied and strong-armed into joining the school team, her two close friends rally to her defense, daring to oppose the Absurdly Powerful Student Council. However, rather than see her new friends suffer for her truculence, this character agrees to join the team, and become its lynchpin.

6) Normally, when girls fight, there's the flailing and the clawing and the clothes-ripping and the hair-pulling. Not here: when these girls fight, they shoot at each other! With some mighty big guns, too. Fortunately, they use Magic Bullets that, at worst, leave bruises and smudges. Nobody dies or even bleeds.

I give up. I looked up every possible lead, and there was nothing.

Something about these clues seem very familiar. I think I saw part of this one. Time to wrack my brain.

I found one possible answer, but I'm not totally sure about it.