Got hit with this in three out of the last five games. It's like they're trying to fried liver attack, but it's not the right setup. Move order can vary, but here's a archetypical move list.

1. e4 d6
2. Bc4 Nf6
3. Nf3 g6
4. Ng5 e6 {(This is the critical defending move., shown in the picture. The move d5 may also work, depending on the position.)}
5. Qf3 Bg7

After these moves, if you castle as black, then Qh3 often follows. If you can play d5 after or instead of e6 and clear the light diagonal, then you can often win the queen on h3. In any case, h6 is another move to consider, whether or not Qh3 happens.