Handplates > Mercyplates
Variants in which Gaster chooses Mercy and raises the brothers as a dad. Since he can technically choose Mercy at any time, the scenarios that result can differ... the two main ones that keep showing up are
a) one where he spares them when they're babies
b) one where he spares them at some point after the beam incident.
Since he's never erased in timelines where he chooses Mercy, he has his normal head (usually).
Just put your arms together and squeeze zarla 2,704 332 Void where prohibited zarla 2,123 192