if you're curious about the pig, watch a little farther in the intro and you'll see him again

the point of naruto transforming into a fox is that its the actual "demon fox".....which has 9 tails.....
its hard to see where the tails are in the manga cause you dont get a good view, but it would be pretty dumb to try to pull off a very symbollic event like this henge and then just barely miss the nail by making them transform into "just some regular fox"