The octonions are a noncommutative nonassociative normed division algebra over $\mathbb{R}$. Multiplication distributes over addition. Somehow, the existence of a norm implies the existence of multiplicative inverses.
Since multiplication is not associative, the nonzero octonions are not a group, but a loop. I wonder if the octonions can still be regarded as a "field", though, or if there's a more proper name for them.
You have answered your own question since a field must have an associative product, yet the octonions are not associative.
Although multiplication is not associative, it is alternative and flexible.
Suppose $x$ and $y$ are elements of the octionions $\mathbb{O}$.
Then
The first two properties make $\mathbb{O}$ alternative the third makes it flexible.