I created a bunch of "hybrid" creatures for a scenario I was making where a mad druid combined people with animals. These are two of them.
The first are Spider Spawn. These are women merged with spiders. They seem easy to kill at first, but when they die, they revert to a pulsating web cocoon, which eventually respawns them as giant spiders (and every now and then a queen). This erf also comes with several cocoon varieties, including those with old dead human victims, those with still living animal victims, and those with still living human victims. There is also a cocoon that is a Spider Spawn before they hatch. Passing near it without using Stealth will cause them to hatch... There are two types of Spider Spawn provided here. Both looks the same, but one drops down from the ceiling or treetops, and the other hatches from cocoons.
The second creatures are Wolfin. Wolfin are men merged with wolves. They are immortal unless the fatal blow is dealt with fire or a weapon made of gold. The Wolfin Masters will often revert to wolf form when damaged, and then back to humanoid form to heal themselves again. They can only do this twice a day. Wolfin and Wolfin Masters are extremely difficult to kill and expert swordsmen, and recommended only for advanced characters.
Both creatures come with encounter templates. The Wolfin one comes with a few sample gold weapons (Any weapon with "Gold" as the first four letters of its tag will work) and you have to place a sound object (also included) in whatever area you want the wolfin to appear in if you want sound effects when they arrive.
Will work with any version, and doesn't require any haks.