Quick tally of the remaining creatu MPs on the site (as of initial post):
Berrok: 115
Chimby: 134
Drindian: 152
Gondra: 106
Intes: 168
Kayoki: 191
Meragon: 207
Mirabilis: 277
Otachie: 162
Paor: 212
Tesuri: 214
Valabex: 152
Vogar: 166
Zenirix: 143
In all, there are 2,399 creatu morphing potions remaining on the site. Of those, only 21 are for sale in shops. As it's been around fifteen years since the Referral Shop closed, the majority of the remaining MPs are likely located on inactive accounts.
Now, I've just recently started morphing pets in an attempt to get a glitch color to fill my collection, but I know others that have done it. I just started doing it within the last two days, in fact, and I've already used two creatu MPs, because I got a RMP'd a Viarindi although I was trying for Veram, and I like Viarindi. If I got Wyrae at any point, I'd be forced to start over with a new pet and creatu MP because you can't morph a Wyrae.
Therefore, my suggestion to combat the low amount of MPs circulating on the site: Bring back creatu MPs to the Vintage Golden Bags. There would be a very low chance of drawing one, but at least there would be new potions in circulation for the people who are interested in these morphing projects. As there are 14 types of creatu MPs, a random selection of 3-4 MPs could be added to the bag at a time, swapping out every few months or so.
Alternate suggestion: When I brought this up, Avedori suggested a potential very expensive way to craft a creatu morphing potion. The idea I've come up with for this is:
Creatu Essences, available from either the Cash Shop or Kir's Quest. When combined with a (magical?) natural squishy of that creatu and a Random Morphing Potion, it turns into a morphing potion for that creatu.
If anyone has any thoughts, concerns, or suggestions for other crafting ideas, please let me know! c: Thanks for reading.