If you want to focus on the animal:
* Mustelids: This is the family that weasels belong to, which also includes badgers, otters, and wolverines.
* Ferrets: These are domesticated weasels, so they are closely related but not identical.
* Stoats: These are a specific type of weasel found in Europe and Asia.
* Polecats: These are another type of weasel, typically referring to the European polecat.
If you want to focus on the negative connotations of "weasel":
* Deceiver: This emphasizes the cunning and untrustworthy nature often associated with the word.
* Trickster: Similar to deceiver, this highlights the manipulative and sly aspects.
* Snake: This is a more figurative term, but it evokes the same sense of danger and untrustworthiness.
If you want to focus on the positive connotations of "weasel":
* Agile: This emphasizes the weasel's quickness and ability to navigate tight spaces.
* Resourceful: This highlights the weasel's ability to adapt and survive in difficult environments.
* Clever: This emphasizes the weasel's intelligence and ability to outsmart its prey.
Ultimately, the best substitute for "weasel" depends on the specific context and the meaning you wish to convey.