HELP!!! Terrorizing Kujo and Tonka

 you may have tried this already, but what about teaching him a good "come" and then try to make yourself more entertaining, like with treats or toys... this worked for Ollie when he was a puppy and tortured our old cat (she was declawed when we got her, so when she'd swat at him it did nothing, and he actually thought she was trying to pet him and would just scoot closer... it was hard as hell not to laugh when you saw it). eventually he left the cat alone just because he thought she was boring.. he would still try to get her to play, but walk away after a few seconds of hissing and come over to me in hopes of a good game of fetch or something, knowing his chances were better with me.

 What have you done to TEACH leave it?  Or are you just saying it whenever he goes after Tonka?  How does he know taht leave it means... well, to "leave it"?

I agree with tethering him to you, to stop him being able to "practise" these unwanted behaviours.

Does he have a crate?  All puppies need downtime.  This would give Kujo and Tonka a break from him.

The cats should have a safe area that Joker is not allowed in.  It's all very well thinking that 2 of them can look after themselves... but it is really better to give them the option of Flight because cat scratches/bites can be very nasty.  And as you've seen, Tonka really NEEDS somewhere she can get away.

What games do you play with Joker that give him a suitable outlet for all this rough housing?  As zloca said... playing these games with YOU needs to be more interesting, so that you can maintain a degree of control.  It will also mean he is easier by far to train.

 He has a crate.

The cats are outside but they have access to the sunroom if they want.

He does great with "come." 

I havent actually taught him to leave it yet. We are still working on that. He's a little food hog and I've been putting food on the floor and working with him that way. Trained Lillie like this and it showed yesterday that it works. Put that in another post.

Me and Samantha both play tug,tag,fetch,go for walks,hide treats so he can find(really really good at that).

 When you teach "leave it", be sure that you aren't just having the dog "leave" one food item and get nothing in return.  You won't get the behavior strong enough to have a dog leave a cat that's running.  The idea is to have the dog think that YOU always have something better than what they left.  I teach this by tethering the dog to me, and tossing the forbidden item just out of reach.  I let the dog decide to turn his head, then I cheerlead him back to me and he gets the better item.  I don't pull, say his name, or anything.  I just keep saying "leave it, leave it, leave it..." until he looks back at me like I'm some kind of nut, then I catch that moment to entice him, by talking to him, backing up and having the treat at the ready.

So, if the dog leaves a biscuit, you have a Charley Bear treat, he leaves the Charley Bear, you have cheese for him, he leaves cheese, you have roast beef, he leaves roast beef, you have tripe, etc., always upping the ante.  When your dog leaves the forbidden item, you can cue "goooood - take it" as he gets to you for the good stuff that he *knows* you have for him.

Once a dog is confirmed in this belief that the human is the bearer of the best stuff, then it's easier to call him off a cat - and he'll forgive you for only having a kibble instead of filet of kitty.  But, it takes lots of practice, and NOT allowing the dog to practice obsessing on cats.

 Ok thanks Spiritdogs!!! I will start that today!!

In addition to SP's great advice (which is crucial) I just wanted to point put some other things to give the rest of your pack some rest.

-Give Joker some one on one time with you. Its much easier to train him with the other dogs out of sight, to strengthen your bond. and give the other pack members some peace. Outings to the pet store and playdates with dogs outside of his pack are always beneficial.

-I firmly believe in letting dogs work things out for themselves as long as there is no aggression HOWEVER I feel that there are things you can do to help the other members of your pack strengthen their position. For example its very easy for us to give into a puppies request for attention but keep a keen eye out so that you dont send wrong signals. For example if you are loving up one of the elders and Joker runs over vying for attention dont let him think its ok to be pushy for attention.

-Use your pack's good manners to teach Joker what is good behavior. I'm sure your pack knows sit/stay. After Joker knows the basics, grab some treats and practice with Joker in tow so he see's the others get rewarded for good behavior and to teach him how to wait his turn and work as a pack. Sit/stay can also be used in the example I described above when your doling out attention.