That's his draw, an extendable neck and hard jagged shell! Like I said he would be very similar to Baragon/anguirus a small scrappy monster. So you would have your shell attacks, claws and kicks then his neck attacks! I will make a move list when I get home!
You have a decent grasp I'll give you that.
And blackout, you have to really look at the creature.
(Just a example pic)
Beyond the extending neck attacks, look at the monster's shell, that aspect alone can give ideas for more attacks. Anything ranging from ramming, to shell crushing, to possibly any forms of body slams. Thinking out a moveset might be slightly troublesome, but it can be done. I think I will take a shot at giving this kajiu a moveset as well.