Spike released a preview of Ferguson's performance of "Take a Chance on Me" Monday.
"Craig Ferguson wins our hearts with a BEAUTIFUL kitty cat dress for ABBA's 'Take a Chance On Me.' Trust us, it gets even weirder. See for yourself when he joins Jay Leno for a new Lip Sync Battle," reads a message accompanying the clip on YouTube.
What song Leno will perform remains a mystery for the time being.