In Reality: Centuries Old In Their Mind? Four

When Nine and Ten are mysteriously drawn to Eleven's location on the planet of Chicago, they thought it would only cause a small, fixable paradox. Once toxic gas finds its way onto the TARDIS, the Doctors are quick to reassure their companions Jones, Tyler, and the Ponds that its harmless to humans; not deadly to Timelords. So now, 9, 10, and 11 look and act age 4. Deaged!Doctor