User blog comment:Kogath/Monster Hunter X Discussion/@comment-4969421-20151127220314/@comment-5569775-20151128101915

Laken: Regarding the yellow fin when it's enraged: it's damaged/wounded. Apparently the wound interferes with the color change and it goes back to yellow. They also damaged/wounded it the second time while it was fatigued, while the Efenbaum was attacking it's back leg, so I'm not sure if it turns blue, or if it would stay yellow then too.

As for the red bubbles, they could be from wounding a fin, maybe it's blood is mixing with the bubbles and it has an empowering effect. It might be best to wait for in game information or a monster book.

Regarding Tama as a whole, I love the theme and I already liked the name(one of the names I hope stays the same if X comes to the west), also it does look pretty awesome when enraged.