Reality is for a million and especially if the $$ was guaranteed before hand I would probably do anything except that which would likley guarantee jail.
To be honest is someone was prepared to pay me that sort of money to do something kinky I'd give the request due consideration provided it didn't harm someone else - no amount of money can justify harming another.
To be equally honest there are a few kinks I'd engage in for free given the opportunity.
While reading the other answers I thought I would do anything for a £1000000. But no I could not do anything with an animal. Beastialluallity is not best. maybe its a British thing
If it did not involve permanent damage, involve a massive portion of my life or freedom (ie jail) or hurting someone unsuspecting, chances are good I would do it.