I was letting Simyukkuri run and I found a wormshape Marisa in my little "clan". Game says it's a Kotatsu Marisa, so looks like it's a hybrid of one and a normal Marisa.
3 hybrids. Okay, how long would it take to get a single hybrid, let alone three? Some people just enjoy RNGesus's bias.
It normally takes me about 20 minutes in a fresh start game, with constant forced refreshing to get 1 hybrid if I run the game at max speed and with orange diffuser constantly preventing the need to feed them and a aging defuser to accelerate yus to breeding age for more forced refreshing.
Once you get a hybrid just keep breeding it until you get another hybrid. Then you can breed both hybrids and you get a hybrid batch 100% of the time.
----- If I am lucky, I get a hybrid in 3-5 minutes while running the game fresh at max speed using the same aging/orange diffuser combo but that is more often an outlier based on my experience. --- The real challenge is getting a pure dosu that does not have any shitty traits though. That normally takes me several hours of constant marisa surveilance.
(Technically you could breed the shitty dosu with a hybrid and get a hybrid dosu that you can keep on breeding until you get good traits but they are not valued as much as a regular dosu marisa, even the shitty ones).