Died February 21, 2012.

Jack Osbourne's adorable bulldog Lola -- who famously tore up couches and peed all over the place on the family's MTV reality show -- has died at the age of 12. Lola wasn't just a reality star ... she was a Twitter sensation as well, racking up more than 8,800 followers.

Jack broke the news ... tweeting, "Thank you all for the kind words about @PrincessLolaO it's nice to know she was loved by so many people." He added, "Lola you were the best friend anyone could ever have. I will love you and miss you always. RIP @PrincessLolaO 00-12."

Lola's Twitter page was also updated with a message ... reading, "Thank you ALL for your kind words. I'm in a better place now. Heaven needs a new princess : )"