This is a posable action figure from the Nendoroid series.
From the GoodSmile website:
From the movie 'Suicide Squad' comes a Nendoroid of one of the most popular DC Comics villains--the Joker! The maniacal expressions of the Joker have been faithfully recreated in Nendoroid style, but have a very unique feel to them that shows an all-new potential for the Nendoroid series! He comes with three face plates including a smiling expression, a shouting expression and a glaring expression. Optional parts include a razor and electroshock tools.
A selection of the various tattoos on his body and face have also been included on the design to bring out as much of the Joker as possible in Nendoroid size! The figure is also fully articulated and features slightly longer hands and feet compared to standard Nendoroids, keeping the "chibi" size while also preserving the bizarre side of the Joker for fans to enjoy in their collection!