Tweedledum and Tweedledee
Concise Oxford English Dictionary © 2008 Oxford University Press:
Tweedledum and Tweedledee/twiːdlˈdʌməntwiːdlˈdiː/
▶noun a pair of people or things that are virtually indistinguishable.
– origin orig. names applied to the composers Bononcini and Handel, in a 1725 satire by John Byrom; later used for two identical characters in Lewis Carroll's Through the Looking Glass (1871).
'Tweedledum and Tweedledee' also found in these Oxford entries:
