Ursine Monstrosity

If, during your declare attackers step, Ursine Monstrosity is tapped, is affected by a spell or ability that says it can't attack, or hasn't been under your control continuously since your turn began (and doesn't have haste), then it doesn't attack. If there's a cost associated with having Ursine Monstrosity attack the chosen player, you aren't forced to pay that cost, so it doesn't have to attack that player in that case either.

If your turn has multiple combat phases, Ursine Monstrosity's last ability triggers at the beginning of each of them. Ignore any choices made for its last ability during previous combat phases.