Okay, so I'm making a Shaman to play in a friend of mine's game, and I was looking for help designing a new Mentor Spirit / Totem.
I'd like him to follow Weasel. The closest I've found is Trickster. But I don't think it's the best fit.
So I call out to all the imaginative and to the veterans (I'm looking at you, Ancient History )out on these illustrious boards as a cry for help.

Help me make a Weasel totem!

I'd like to help, but I don't know anything about the Weasel archetype. Can you tell us more about Weasel?

I R Weasel?

Weasel is known for being observant, so I'd go with +2 to detection spells. They are also fighters, so I'd go with +2 to summoning Beast spirits.

I'd say that if cornered, they'd need to make a will + cha test against having to fight their way out of the situation.

I found this website: http://www.manataka.org/page236.html#WEASEL Assuming it's pretty accurate, here's my thoughts.

It seems to me that mentor spirits all have +2 to two different things and either a -1 to something else or a Willpower+Charisma (3) roll. Noting this, I attempt to pick and choose from different mentor spirits in order to throw something together:

+2 to Perception and Assensing Tests (Owl from Street Magic)

+2 to either Infiltration or Gymnastics, pick one (Cat)

I'm still thinking about disadvantage but I'll post this now.

Cha+Wil (3) test to back down when outmatched/to not attempt something outside your ability. Perhaps even forcing high F spells because weasel thinks he can handle it.

Who's going to hunt for his MitS? Didn't they have a write-up for Weasle-Totems?

I'm afraid not, I just checked.
It isn't in Awakenings either, which has a totem index for the SR1/2 sources such as the Grimoire.