It is possible to have one of these little guys as a pet but you would definitely need to get a special permit from your country, state, or local government. In addition you would need to make sure you have a trained Veterinarian (who is familiar with the Pygmy Marmoset) available as these little guys require very unique and special care.
Want to raise one from a teeny tiny baby? They need to be fed every 2 hours for around 2 weeks - who would have thought a little guy like this would need so much little food?
It is also important to pay close attention to the Pygmy Marmoset when you care for them - otherwise you might get a teeny tiny little bite, or an eye full of teeny tiny little fæces.