system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When two "incompatible" animals crossbreed, at which point does the process fail?

Joke answers aside, if two distant animals mate, how early or late in the process will the offspring fail to form?

Will it be as early as the sperm not even being able to penetrate the ovum?

Will the zygote form, but be unable to successfully dvide?

Or will there briefly be a hybrid baby, but too deformed to possibly survive?
gpt
Usually it fails very early in fetal development. The sperm might penetrate the egg, but the resulting zygote has broken genetics that don't allow it to multiply properly in a way that creates a viable living creature.