Using Skinshifter's ability when Skinshifter Attacks

Question

I was wondering what happens when I attack with Skinshifter. Imagine the following situation.

I attack with Skinshifter and in the assign blockers phase my opponent blocks Skinshifter with Runeclaw Bear. Can I say that I use Skinshifter's ability to turn him into a Rhino?

Another situation. My opponent attacks with Runeclaw Bear. I block it with my Skinshifter. Can I turn him into a Plant when I assign my blockers?

I assume that Skinshifter haven't used his ability in that turn.

Answer 1

Yes, both those situations would work. Skinshifter's ability can be used at any time you receive priority(i.e any time you could cast an instant). After both the Declare Attackers step and the Declare Blockers step, players receive priority.