There are several Battle Emotes for you to select from in Ninjala, with ‘Na-Na Boo-Boo’ being one such option.
By going into the Closet and then the Battle Emotes menu, you can change either your battle start, victory, or defeat option to Na-Na Boo-Boo.
‘Na-Na Boo-Boo’ Official Description
“Quickly hide and unhide your face and stick your tongue out. Tease someone like a naughty little kid.”
‘Na-Na Boo-Boo’ Animation
The Na-Na Boo-Boo is one of the more taunting Battle Emotes available, with your ninja pulling a silly face to rile-up your opponents.
If you want to taunt the others, this emote pick will suit the pre-battle and victorious options.