Bruce's response to the griffon is... interesting.

There's something some defensive response back - red washes over his eyes with a dull glow that entirely obscures the more human appearing dark brown and there's something in the way shadows perceptibly deepen around him, and suggestion of movement within them from behind him.

But the expression on his face isn't defensive, threatening, or anything of the sort. Even with hellishly red eyes, and the griffon flaring wings and glaring, Bruce just looks... fascinated.