^

Tanks with CC and slows.

Jarvan, amumu, sejuani

Anyone with an aoe cc i guess?

Have you seen Amumu Ult -> Kat Ult? WOW, FANTASTIC BABY!

Anyone with hard cc is good with Kat, as has been said.

But you can also use mana-hungry junglers with her, as she does not benefit from blue buff's mana regeneration.

*ahem* Amumu.

Skarner is good

I prefer Sej over Mumu with a Kat; Sej's ult is actually a stun and she has a displacement and a slow while Mumu's ult still allows most champs to interrupt Kat. Regardless, I still hold to my earlier statement.

I play lots of Katarina

I would say maokai / nunu / other champions that can snare somehow for katarina to get in range of her w are excellent.