How do I get

[Cain]

How do I get a Razorback ??

[WalkinTarget]

Pure luck. The drop system is nothing but, so getting one is just matter of playing a LOT.
I've gotten so many drops that I can no longer carry new ones, so last night in the middle of a tight round I had to start deleting what I knew was extra. You can't gain access to your items until you've just received one, so that's a bad time to be scrambling to clean out extras.

Also, the Razorback is of limited use in my experience. I would MUCH prefer the Jarate and accept a few backstabs. Those mini crits combined with an ubered Heavy can take out a wall of guys on the cart in 5 seconds flat. Besides, how can you go wrong with an autotaunt that yells out 'Taste me piss, ya wanker !!'

[Queen B]

You also get it with the sniper milestones achievements ;D. All the extra equipment can be either got through doing that or with pure luck as WT said.

Sniper Milestones Achievs:
5 achiev - Hunstman
11 achiev - Jarate
17 achiev - Razorback

And yeah, well, the razorback does defend you from 1 back stab. But... Spies are all around, and they could face stab you too!!!

[Pumpkin_Jack]

And yeah, well, the razorback does defend you from 1 back stab. But... Spies are all around, and they could face stab you too!!!

Or as the one spy achievement is you might get plucked in the skull by an ambassador.