@Weird TalesActually, your idea
can work. However, not in the way you want it.
See, I've done a bit of world building, and in that world building I have accounted for humanizations/anthropomorphisms of animals for just an occasion.
Alright, so in the multiverse, portals open up to people desiring an escape. This can mean a lot of things, like getting out of a bad situation or wanting to see the world or doing something with their life. So long as someone possesses a strong escapist mindset and if the person making the portals wants to make their dreams come true, they'll get portal'd to another world.
However, animals tend not to have this, due to their instinct and non-sapient nature. However,
some animals
are sapient enough to give off the same escapist desires that humans can present. While the portal'n on animals more likely applies to talking animals, I would say that it can work on the weasel provided it possesses the escapist ideals.
And thus, the weasel gets portal'd to whatever world you want and in the process of the dark portal nature (the portal connects to a dark sea of abyss that acts as a hyperhighway to other worlds), transformed into either a humanized version or in your case, anthropomorphized version. Would that work?