Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bc4/3...Nf6/4. Ng5/4...d5/5. exd5/5...Nxd5/6. Nxf7/6...Kxf7

=Fried Liver Attack=

6 ... Kxf7
No sensible alternative to taking the Knight with the King.

=Theory Table= .
 * 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nxd5 6. Nxf7 Kxf7