So I know, in the FAQ it lists "You can also change an existing pet into a bumbus after you've received the random event from a group of bumbii to visit the Bumbus Queen."
I plan on making two of em, but I was wondering
Entering the bb is a one time password. O e you don't even have to remember. As far as making a hummus personally I got mine (Rumi) via a SUPER rare zap. It can't be any worse of a wait to do over an existing pet than say steamwork, nostalgic or aeanoid where we have to wait a bit to get them. I really don't know if its as instant as say using an elixir or a wait like those.
FINALLY GOT THE 15K WARDROBE DONE!!!!! Next up gutting and selling it.
once you've gotten access to the blue building, you can create a bumbus any time you want, as often as you want - as long as you have available pet slots.
if you want to change an existing pet into a bumbus, you have to wait until you get the bumbus queen random event (though you may have already gotten it; as far as i know, you can get the event before you even have access to the blue building). if you've gotten the event, you can visit the bumbus queen at the blue building and complete her quest, which consists of her asking for three moderate-to-high-priced items (the quest i currently have active, which i have not done because i don't want a bumbus at all, is asking for a bag of cranberries, rose quartz leaf-tipped earrings, and krunchy keith-os cereal). once you've completed the quest, you can choose a pet to change into a bumbus. if you want to change another pet, you have to wait for another random event "summoning" you.
so in short, it's easier to create a bumbus than to change an existing pet into one. and the password is just an event you need to get into the blue building itself; once you're in, you can visit whenever you want. you don't even need to actually know the password you get, as it will automatically grant you entry.