Note: This idea is about the blood blob ghosts thing that floralflowerpower , mokulule kii0mi and others came up with on Tumblr. It's kinda cursed so I apologize in advance. What if it was combined with five-rivers 's womb room idea?

So bleeding, intentionally or unintentionally, can lead to blob ghosts forming which is how ghosts reproduce. If there's only one ghost, one ectoplasm source, then this is basically a form of asexual reproduction. But blob ghosts are the first step. At the beginning, they're basically embryos or eggs. And most don't make it past this first stage. They wander away from their parent or are abandoned. A lot of them get eaten, kinda like fish eggs that get eaten before they hatch. It's not a huge deal (for ghosts that produce a lot of blobs at least) because at least a few will survive.

I'd say that more applies to animal-like ghosts though. For humanoid ghosts, care and attention of a parent is very important. Most don't make blobs by accident and carefully plan when and how many they will have. After the initial spawning, they'll spend time with their small group of blobs. They'll observe which ones are the strongest and most stable, which ones start gaining humanoid characteristics resembling the parents. These ones are the most likely to succeed in the next step.

Now, parental care after spawning will increase the chance that a blob will survive and the blob will start to resemble the parent. But blobs will not go from this embryo state to an actual baby ghost unless they are wombed. The parent will set up a room in their lair for the blob where they feed it and go through steps and rituals meant to trigger the metamorphosis from blob to infant. If it works, the parent will have a baby ghost (or two or three depending on how many blobs they started with). But this means that no ghost becomes a parent by accident.

Now the implications for Danny… so he starts with a gaggle of 15 or so blobs from a big battle when he's 16 or so. He recognizes that they're his. They came from his blood and he adopts them. They follow him around and Danny talks to and plays with them. He loves them very much and jokes about them being his kids but really…they're more like pets. And that's okay. That's a natural reaction for a ghost at his level of development. He's not ready to be a parent and won't be for a while.

Now sadly, the group dwindles. Some wander away, back to the ghost zone. Some are eaten, even by their siblings. Danny's parents even manage to catch one. That was a really bad day for everyone. Occasionally, a few are added to the group but as Danny gets better at fighting ghosts, this happens less often. Danny ages and his group of blobs ages. With his attention, some of them gain human-like characteristics. One almost has Danny's hair. One has a single tooth in its mouth. One has Danny's eyes. It's nice. Danny's happy with the group and he loves them very much but…

Blob ghosts have a shelf life. Maybe a few months, maybe years. It's longer the more powerful blood they come from but it's been years for Danny and his blobs and… some of the older ones are less vibrate. The half ghost is horrified when one of them dissolves into a puddle of ectoplasm. He's devastated and goes to Frostbite for advice, for a way to save them.

But the truth is, the group is reaching the end of their viability. It's been almost ten years, impossibly long for blob ghosts. Danny is in his mid twenties and he knows…he knows what's happening. Frostbite explained the ins and outs of ghost reproduction to him years ago, after his first group of blobs spawned. And now the yeti gives him an ultimatum. Danny can let them go. He can let nature take its course, allow his blobs to fade and disappear. Or… he can do what he must to save them. They must be matured. Danny has to womb them. The thoughts make a knot form in the half ghost's stomach.

Frostbite is understanding. This is a big decision, a monumental decision. If it works, Danny will not have blobs but children, his own children that he will have to raise. But the yeti is also stern. If this was any other being, he would think this hesitation was cruel. Ghosts do not nurture their blobs, only to abandon them at the end of their viability. It would be cruel to do so, to put so much time, effort, and love into almost-children, only to deny them their true form and personhood and end their existence prematurely. But Danny is not cruel and the yeti knows he will make the right decision.

Danny goes home and talks about the decision with his significant other and the pair make a choice. The next day, Danny returns to the Ghost Zone. He gathers his ghostly guardians, Clockwork, Frostbite, and Pandora, and returns to his lair to prepare the nursery with the older ghost's guidance. Once everything is ready, Danny and his partner bring the three remaining blobs. They set up the trio in the middle of the room, in something that's the impossible mixture of an artificial womb and a crib. With the blobs in place, Danny begins. The air is thick with energy, humming with the sound of his core. Everything is in order and the other ghosts leave. The half ghost stops the Master of Time.

"Clockwork….will they be…like me? Half ghosts?"

The blue skinned ghost just winks and leaves without a word.

Danny and his partner stay in the lair for weeks. He talks to the crib, sings to it. The half ghost puts his hands on the glass separating him from the forming cores and he pictures what his kids will look like. He waits, pouring himself into the process. He never strays far, even sleeping on a cot only feet away. The days drag on and on and Danny and his significant other are full of nerves, as the area inside the incubator swims with ectoplasm and hides the progress inside. The half ghost almost thinks it will never end, that he'll never see the result of this metamorphosis from blob to infant ghost. Until he awakes to the sound of babies' cries and a flash of white light.