The Pandorica Opens
The Zygons are briefly mentioned (but not seen) in the Eleventh Doctor episode "The Pandorica Opens" (2010) as one of the many races in an alliance against the Doctor. In the 2012 episode, "The Power of Three", a Zygon ship is hidden beneath the Savoy Hotel where the Doctor takes Amy Pond and Rory Williams on their wedding anniversary. All the Zygons are disguised as hotel staff.