Here is a siabrae, which is basically the lich version of a druid. It has some unique powers, like its horns that appear on any beast transformation allowing to impale enemies, more resilient transformations, and plenty of other cool things, like necromancy!
Unlike a lich though it's not outright Evil, although it is very territorial.
I created a full Prestige Class to become a Siabrae which you can find on my Patreon if that interests you. The Book of transformation will release tomorrow there as well.
When the demon infestation started, the druids fought longer and harder than any other citizen against the rising demon tide. Those druids who stubbornly (or faithfully) refused to flee their sacred lands managed something that few others did—they prevented the wholesale invasion and corruption of their land from demonic influence, but only at a terrible cost. They took the corruption into themselves, and today, these druids exist as blighted, undead parodies of their former selves. Known as siabraes, these powerful druids have embraced undeath, bolstered with the strength of the wounded-but-still-living world beneath their feet, and fight not only against demonic trespass into their realm, but against all living creatures, for they are filled with bitterness and hatred for their brethren, whom they regard as cowards. The druidic faith was meant to die, the siabraes believe, for the truth and glory to emerge.
The Lore was created by Paizo Publishing, btw, but the statblock is all original!