6649-4.04: You get attacked by a mammoth
Update: it's not going well.
Seriously though, I doubt this was meant to be an option - I think this is a glitch in the domestication system since no actual project turns up when I select the 'Taming' option. If someone could confirm that'd be great.
(Also, out of interest - just how much beef would I get from a domesticated mammoth?? Local omnivore wants to know.