Okay, I tried them all again. Here's what happens.
LeurreAnimal1: Looks like a stag in your hand, but looks like a vulture when you place it. Vulture sinks into the ground upon placement, but block is still invisible and you can't pass through it. Destroying the block beneath it is the only way to get rid of it.
LeurreAnimal2: Just an invisible block. Destroy it by destroying the block beneath it.
LeurreAnimal3: Looks like a boar, seems to work fine.
LeurreAnimal4: Looks like a pig. It seems to work at first when you place it, but becomes invisible when you turn your back. Block is still occupied until you break the block beneath it and destroy it via fall damage.
LeurreAnimal5: Looks like a vulture in your hand. When you place it, the vulture sinks into the ground. Block space is still occupied until you destroy the block beneath it.
Pig Trough: Same as LuerreAnimal 4, but the pig reappeared briefly when I walked against it and destroyed the block beneath it.
Stag Trough: Seems to work, though its face and neck look glossy.
Rabbit Trough: Works at first, but becomes invisible when you turn your back. Destroying the block beneath it gets rid of it.
Chicken Trough: Chicken falls through the world upon placement. Destroy the block beneath to get rid of it.
Snake Trough: Seems to work, though snake doesn't animate.
Now for the zombie things.
LeurreZombie1: Looks like a Wight when you hold it in your hand, but placing it seems to spawn a different zombie each time.
LeurreZombie2: Looks like a Zombie Boe, seems to work.
LeurreZombie3: Zombie football player, seems to work.
LeurreZombie4: Big Momma, seems to work.
LeurreZombie5: Zombie Joe, seems to work.
LeurreZombie6: Zombie Moe, seems to work.
LeurreZombie7: Zombie Arlene, seems to work.
LeurreZombie8: Lab Zombie, seems to work.
LeurreZombie9: Screamer, seems to work.
LeurreZombie10: Zombie Darlene, seems to work.
LeurreZombie11: Zombie Marlene, seems to work.
LeurreZombie12: Zombie Yo, seems to work.
LeurreZombie13: Zombie Steve, seems to work.
LeurreZombie14: Also a Zombie Steve. Possibly meant to be the crawler?
LeurreZombie15: Businessman, seems to work.
LeurreZombie16: Lumberjack, seems to work.
LeurreZombie17: Spider Zombie, seems to work. He stands in the same idle pose as the other zombies rather than his unique stance on all fours. It's how I figured that Zombie14 might have meant to be the crawler...
LeurreZombie18: Burn Victim, seems to work.
LeurreZombie19: Zombie Nurse, seems to work.
LeurreZombie20: Disturbed Tourist, seems to work.
LeurreZombie21: Zombie cop, seems to work.
LeurreZombie22: Hazmat zombie, seems to work.
LeurreZombie23: Utility Worker Zombie, seems to work.
LeurreZombie24: Fallen Soldier, seems to work.
LeurreZombie25: Demolisher Zombie, seems to work.
LeurreZombie26: Skateboarder zombie, seems to work.
LeurreZombie27: Cheerleader zombie, seems to work.
LeurreZombie28: Zombie cowboy, seems to work.
LeurreZombie29: Biker zombie, seems to work.
LeurreZombie30: Farmer zombie, seems to work.
LeurreZombie31: Stripper Zombie, seems to work.
I think there's also the possibility of these zombie blocks disappearing/going invisible when you leave the area, or perhaps it only happens when you log out. I've only had it happen with the Zombie1 block, but I haven't tested it on any of the others. Anyway, I hope this helps...