I know you probably did this yourself, but to anwser your question I googled it. This website that first came up and my best friend, who i sactually full native american (she gets to go to college for free because of it, not fair!), says that its a legit website with -mostly- legit meanings. http://www.support-native-american-art.com/Native-American-Animal-Symbols.html
Here is what I pulled from it in breif
•Polar Bear: Never gets lost; solitude; expert swimmer through emotional waters; ability to find food where none seems to exist; strength in the face of adversity; communication with the spirit; creature of dreamers, shamans, mystics and visionaries; defense and revenge.
•Weasel: Stealth; cunning; ingenuity; revenge; ability to see hidden reasons behind things; power of observation; Weasel and otter hides, because they come from “tough little animals”, are linked to the Crow sun dance, probably conferring endurance. For the Lakota, these two
You can actually get creative with both of those animals. If it was me I would go with the weasel. They are sly in a way possible for revenge. Sneaky and unlikable.

I hope that helped!