World heavyweight champion Anthony Joshua "fights like a big robot", says Andy Ruiz Jr, who has vowed to "make history" when they fight on 1 June.
Ruiz, 29, has been confirmed as Joshua's opponent for his US debut, replacing Jarrell Miller following the American's failed drug tests.
Joshua, 29, has been installed as a 1-25 favourite with bookmakers.
"My whole life people underrated me so I'm going in there to take all," said Ruiz, who has 32 wins from 33 fights.
"I'm not going in there scared and I'm not going in there nervous, I'm going to go in there mad and to take what's mine."
Ruiz, a Mexican-American based in California, is bidding to become Mexico's first ever heavyweight world champion.
In his only world title shot and defeat to date, he was beaten on points by New Zealand's Joseph Parker, who later lost his WBO title to Joshua.
"There's nervousness in me, but they're happy nerves," added Ruiz. "This is my chance to make history.
"I think the fight is going toe-to-toe, two guys smashing each other's faces. I'm going in there to throw combinations like I've never done before, to improve my speed.
"I think being so tall he fights like a big robot. I think with my style, my speed, my movement, I don't think he's fought anybody like me. It's going to be a whole different ball game. I'm going to bring the pressure, the speed, and the combinations to him.
"When I do pull out this win, everything is going to change. I'm going to bring the titles back to Mexico, it's going to mean everything. I'm going to be able to change my whole family's lives; my life and all my kids."
A tougher test than Miller?
Joshua has not fought since his impressive stoppage win over Alexander Povetkin in September.
The IBF, WBO and WBA world champion was well into training camp when news of Miller's failed drug tests emerged, prompting a search for a suitable opponent.
"Ruiz is a different kind of challenge but one I embrace," said Joshua, who has 22 wins from 22 fights.
"We have worked in the boxing gym week on week and whomever is put in front of me at Madison Square Garden will be dispatched in style. The rent will be collected."
Joshua's promoter Eddie Hearn has backed the champion to use the bout to make a telling impact in the US.
Hearn believes Ruiz is "a tougher test" than Miller would have proven, stating the challenger "punches harder and is much faster".
"People talk about fighting AJ, some even have to fill their bodies with performance-enhancing drugs to try and beat him up, but very few genuine fighters step up and take the challenge," Hearn said.
"Andy brings Mexican heart but he will meet the best heavyweight in the world in June head on at the Garden."