Hey,

iKuehnDE here with a Nunu jungle guide.
Nunu jnugle is always a good choice if you have enough cc in your team, in my last game it was enough cc by Leona and Pantheon, their ults combine really well with Nunu's. I personally pref Nunu vs Ad than vs Ap because my favourite items include more armor than mr.
Kepp one thing in mind: Nunu shouldn't be the damage dealer. He should do a second support (or not), but at least you should NOT try to carry solo. Your W is a great tool to let the ads in your team do more damage in a short time. Your E is a great tool to gank, combine it with the red buff and your W, and the kill is secured.
But lets not longer talk about this, lets start.

Pros:
-Tanky, but still good damage
-Nice utility for your team
-Combines well with current meta supports and tops
-Good jnule clearing, nice dragon control, good for pushing

Cons
-Useless if you can't play it
-Useless if you fall behind

You can clear really fast.
If you start on blue side, i take the red camp first,
and walk over then to the wraiths. Your smite is up then again when you are at the blue buff.
You should try to get the drake early (minute 10), you can easily solo it when you maxed q.
If the enemy jungler is something like amumu (slow clearing), you can try to counterjungle.

Teamwork is really important if you play Nunu in the jungle.
1.Use your W on your adc (or an ad assasin such as zed), so they have improved attack speed.
2.Slow down the Carry in the enemy team with your E.
3.Try to combine ultimates. This works really well with Leona, Lulu, Pantheon, Galio, Amumu, Zyra and also MF if you got one of the others.

You can use your ulti while you are in a brush, so the enemies wont see you. I do this, when I know they do not have vision over it and they will pass. (e.g. the brush opposite the blue buff of purple side when a dragon fight is about to start.

This is the end of this guide. I hope you like it.

iKuehnDE gots ice blasted!!!