Use Animus
Once per activation, at any time, a warbeast can be forced to
use its animus. Instead of gaining only 1 fury point when it is
forced to use its animus, the warbeast gains a number of fury
points equal to the COST of the animus.
The Animus use is an exception because it specifically states that instead of the normal 1 fury, you generate fury = cost of Animus.
And yes, AFAIR the Animus is the only exception.