Disguise
The chameleon circuit provided TARDISes with a disguise which allowed them to blend into their surroundings. The Doctor's TARDIS was disguised as a police box in 1963, and was left stuck in this form as the chameleon circuit broke down. (TV: An Unearthly Child)
Skin suits were disguises which were used most notably by the Slitheen family. (TV: Aliens of London/World War Three)
Historians who had been allowed access to the "Monster Vaults" of the databanks in the Doctor's TARDIS observed that an Abzorbaloff could disguise their form with a morphic illusion and their voice by putting on an accent, but could never disguise their villainous intent. (PROSE: The Monster Vault)