Thus starting Gaster's flailing denial as the wheels continued to come off his plans. You're supposed to be formless and non-sapient, how dare you!!
As a bit of a clarification, Gaster always intended to make a living creature, he just didn't expect it to look like a monster, much less a skeleton. And while he planned on creating a formless, non-sentient being, he still felt like experimenting on a living creature the way he planned to would be wrong, thus his catastrophizing earlier.
well at least they're alive, well at least they don't look like children, well at least they're not sentient, well at least they can't talk, well at least i can wait until they're old enough to understand, wait what am i doing
