Throat Wolf

If a creature with firstest strike enters the battlefield during the firstest-strike combat damage step or the first-strike combat damage step, it deals regular combat damage instead.

If two players each control Throat Wolf, player A’s first combat phase will be followed by player B’s first combat phase from B’s Throat Wolf, which will be followed by player A’s second combat from A’s Throat Wolf. On player C’s turn (where C is the active player and player A is the next player in turn order) player C’s combat phase is followed by player A’s combat phase, then player B’s combat phase following player A’s, then player A’s following player B’s, then player B’s that follows player C’s finally happens.

As the declare blockers step ends, if any creatures have firstest strike, there’s an additional combat step where only those creatures deal damage. The game waits until after this step to determine whether there will be a first-strike combat damage step.