Yeah you want to do a frame-by-frame animation. Here's a simple guide on how to do it; http://developer.android.com/guide/topics/graphics/drawable-animation.html
You can also do things like make it loop, and set the time between each image.
<animation-list xmlns:android="http://schemas.android.com/apk/res/android"
android:oneshot="false">
<item android:drawable="@drawable/my_image1" android:duration="10000" />
<item android:drawable="@drawable/my_image2" android:duration="10000" />
</animation-list>
Use that in your resource file, and then just copy the code in that example.
You could also use a TransitionDrawable but I don't know how you would achieve the looping http://developer.android.com/reference/android/graphics/drawable/TransitionDrawable.html
Here's another question about fading from one image to another, but once again, these are one shot transitions. How to do a fadein of an image on an Android Activity screen? the answer at the bottom might actually be helpful to you.