What's the name of where to make a baby like Baby ChaosFlo?

So Chaosflo44, a YouTuber, has a son in Minecraft, Baby Chaosflo, Flo made him into one of his earlier series with such a Golden Egg. However, I do not know what the mod is saying, where to make a baby with such a golden egg (if you do not understand what I mean Just watch the video: Baby Chaosflo meets Baby Ronja? -Mincraft Phoenix, because he's there at the end of the video Baby Ronja does) Can tell me what the mod is called?

So either Mo'Creatures, Clone Craft, Custom NPC's or My Own People (or something like that, the name is complicated.

His name is Open Blocks, I think