Xu-Fu, Cub of Xuen

Here is my method:

1. Start with Tranquil Mechanical Yeti - because he is slower than Xu-Fu, after Xu-Fu cast Moonfire, the Yeti will cast Lightning. The sole purpose of Yeti is to cast lightning, I know he is mechanical and has the ability to fight Xu-Fu, but don't fight him now. The other alternative is Skywisp Moth.

2. IMMEDIATELY switch to Clockwork Gnome, set up Turret immediately, he may die and be revived.

3. Szechuan Chicken - Once you got the first chance, immediately switch to Szechuan Chicken and Flock Xu-Fu down. He should die on 2nd flock.

No pet should die in this round, he can be downed within 5 rounds.

I used it every time, it never fail :
First open with Sunreaver Micro-Sentry and use Call Lightning
Then swap to Clockwork Gnome and use Build Turret
And last swap to Lil' Bling and use Inflation
GG you just win =)

Easy 2 pet suicide strat if you are having a lot of difficulty without the howl bomb anymore:
Voodoo Figurine/Sen'jin Fetish with Flame Breath, Wild Magic and Rot
Infected Squirrel with Stampede

Use flame breath, wild magic and then rot, you are guaranteed to land all three with no crits but will die. Flame breath doesn't matter, just make sure wild magic and rot are up before you die.
Squirrel uses stampede, you will die, undead racial, stampede again and Xu Fu is dead.