by never feeding it!
you can not level up if your monster is unhealthy or sad
You have to buy really unhealthy things then it turns to medicine and u give it to them
To make your Moshi Monster sick, do not play Moshi Monsters for a long time. If you do play Moshi Monsters, do not do anything that will add Health or Happiness to your monster, such as feeding your monster, playing games, or going walking in Monstro City.
You can't make your moshi monster fat but if you make your monster eat a lot you will make it sick!
You can not make your Moshi Monster run away from home. If you do not play with it or feed it, your monster will become unhappy and sick.
you can not
No
you make your moshi monster ill by neglecting it and not visiting it for a few days. or you can make it ill by over feeding it! I hope this helped :)
You cant.
If you do not play with your monster for about 2 weeks, then it will lose happiness and become sad.
Moshi Monsters don't/can't sit.
If the monster is "not on" Moshi Monsters, then it would be helpful to know which game you are asking about as there are many games that have monsters in them. If you are asking because you have a free Basic Membership account on Moshi Monsters, your monster is "on" Moshi Monsters and you do the same things as everyone else to make your monster happy. That is, tickle your monster, play games, and feed it favorite foods.