Gaster has three forms: Phase 1–3 and Phase 3 Ultra. Its power scales with each transformation. It possesses abilities such as Gaster Blasters and Hand Blasters. There are two ways to trigger a transformation: first, by standing in front of Gaster for more than 15 seconds; second, by killing it, which causes it to switch forms more quickly. Phases 1 and 2 have 5,000 HP, whereas Phase 3 and Phase 3 Ultra are invincible. Give it a try, but please consider your device's safety.