Looks like a variegated Monadenium stapelioides/Euphorbia neostapelioides. Be aware that it bleeds a toxic sap if the skin is cut or damaged.

Warmth and strong indirect light are a must to keep it healthy-treat it like a tropical 3/4 of the year.

I found that a cutting rooted pretty easily. Let it callous over and stick it in some pumice. A little bottom heat can help.

Oh, and don't worry if it loses leaves every now and then.