A TV ad, which launches today, explains that the Argos alien family is expecting a baby and encourages Twitter users to suggest names for the new character, using the hashtag #nameourbaby.
The winning suggestion will be included in the next TV spot, which will break on Saturday 29 June.
Alongside this campaign, Argos has launched a Twitter feed that allows users of the social media site to engage with the existing members of the alien family.
CHI & Partners created the TV and Twitter campaign in conjunction with its social media agency, The Social Practice. The campaign was written by Rebecca Wass and art directed by Carl Winterbourne.
Neil Harris directed the TV spot through Smuggler.
Steve Parker, partner at The Social Practice, said: "There’s already a lot of warmth and conversation about the Argos ads on Twitter, so we wanted to deepen this engagement by inviting viewers and users to get involved in shaping the story of our alien family in a truly dynamic way.
"The creative idea was borne out of our ambition for Argos to operate in real time in a way that boosted brand relevancy and engagement with our target audience."