Yeah I can work with that:

A university archive once full of texts and books and research implements. Now overrun with huge, nearly immortal hogs.

The hogs were bred as part of an experiment. They can digest virtually anything they can swallow. This includes books. When they are full they go into a state of advanced hibernation. Their aging slows in this state. They have an accute tremor sense and wake at movement nearby. This has allowed them to live for a very long time.

The hogs multiply rapidly. There are three or four generations living here, and almost none have died of old age. If they remain here, they will eventually die off from starvation and inbreeding, but that will take a very long time.

One hog has a magical dagger sticking out of its head. This dagger contains the soul of the famous thief Rolando Nin. Nin’s mind now inhabits the hog’s body, enjoying the benefits of both.

Three hogs are half rust monster. This was either another version of the experiment that produced the remaining swine, or they have the power to interbreed. Alarming either way.

edit: some of the hogs got into the alchemy lab. The reagents interacted with their own alchemically-enhanced metabolisms in some dramatic ways. One of them can breathe poison now. Another expanded to fill out the entire lab, where it is now stuck and slowly starving to death.

Edit 2: actually the poison one’s breath isn’t poison, it turns organic materials to gold. This has helped soften much of the wooden furniture, making it easier to eat.