Google could be looking to revive its social efforts, which have lagged behind Facebook as it struggles for a breakout product. Google Plus wasn't it.
Walt Disney and Salesforce have been reported to be exploring a potential bid for Twitter, as well. It's not clear if a bid has been made by any company, as hiring an adviser doesn't signal definite intentions for a bid.
Twitter co-founder Ev Williams in August declined to confirm the social network is seeking a buyer, but told Bloomberg: "We're in a strong position now, and as a board member we have to consider the right options."
Lizard was Google's financial adviser for its $625 million acquisition of Apigee last month.