Red is correct, though it doesn't look like the animations include those. This is what it said at the bottom of 
the thread.
ManPig animations
To be sure the ManPig entity type behaves correctly, the entity should have following animations set in its .ent file:
- IdleBiped
 
- IdleBipedExtra1
 
- IdleBipedExtra2
 
- WalkBiped
 
- RunBiped
 
- FleeBiped
 
- NoticeBiped
 
- ThreatLoopBiped
 
- AttackBiped1
 
- AttackBiped2
 
- AttackBiped3
 
- BiteBiped
 
- ChargeBiped
 
- IdleQuadruped
 
- IdleQuadrupedExtra1
 
- IdleQuadrupedExtra2
 
- WalkQuadruped
 
- RunQuadruped
 
- FleeQuadruped
 
- ThreatLoopQuadruped
 
- NoticeQuadruped
 
- AttackQuadruped1
 
- AttackQuadruped2
 
- AttackQuadruped3
 
- BiteQuadruped
 
- ChargeQuadruped
 
So yeah, I'm afraid I don't know how to do this. It must be possible though. Perhaps the animation is one of these "Extra" ones, but I get the feeling they are just little variations they do at random.