Can butterfly koi and regular koi breed?

Yes. In fact, the gene that controls the butterfly characteristic is a dominant gene so all the offspring will be butterfly.

they grow bigg around 12 inches

Yes they can cross breed.

Up to 36 inches(3ft) make sure that if you have more than one to have a nice big pond for it, like the ones you get at walmart. 50-100 gallons are perfect.

Koi are a cool temperature water fish while African cichlids need warm water. Koi will not be as happy and healthy with 80* water Koi are a cool temperature water fish while African cichlids need...