I believe that it can in a storms of magic game. Not in a regular game unless you use house rules for it. If you run it in a house rule game, use the base stats it has and make it cost what the mount would cost. 210 points may be to few points, but it may be right on since there is no other riders or crew.
The real question would be, why would you want to? The guy hits at I2, and there are a large number of things that will kill him before he even reaches combat. When he does, again there are a number of units, weapons and abilities that can kill him before he can swing. Even in Storm of Magic (which is ironically supposed to be getting sales of monsters up, but just like everything in Fantasy, it boils down to 'who takes better mages and Lores'), I don't see the point. There are any number of better monsters to take, and there is no penalty for doing so (they can all be bound or unbound equally). We already have Stegs for 'big slow monster stomping'. Fast warmachine hunters would be handy, like Eagles. Not to mention the insanity of some of the Bound wizard characters, and the Pact system. If you're still keen on a big fighty monster, Hydra is the way I'd go. It has Regen to keep cannonballs from smashing it into red paste, its still slow but with plenty of attacks, and its breath weapon is handy.