Rampage Jackson Signs Rival MMA Deal After UFC -- It's a 'Dream Come True'

Former UFC fighter Rampage Jackson is BACK -- officially signing a brand new deal with TNA wrestling and rival MMA company Bellator ... and he tells TMZ, the new contract blows his UFC deal out of the water.

Rampage tells TMZ, "When you look at my deal in the UFC, and the scope of what my deal with Bellator and TNA is, this is a dream come true."

He adds, "When other fighters get the chance to see everything I'm able to do with this deal and the benefits it provides, you're going to see a big change in MMA. I guarantee it."

Rampage left the UFC earlier this year on bitter terms ... telling us, the UFC treated him like crap and screwed him over financially. UFC honcho Dana White shot back, implying Rampage was an overpaid wash-up.

Under his new multi-year deal with Spike TV, Rampage will compete in Bellator and also appear on TNA's "Impact Wrestling." He also gets a reality show. So far, no word on how much he's getting paid.