Overlord: Ple Ple Pleiades - Nazarick Saidai no Kiki

オーバーロード　ぷれぷれぷれあです 『なざりっく最大の危機』

Bundled with novel series' 11th volume. The new anime will feature the appearance of the Pleiades combat maids, as well as the rest of the Floor Guardians. (Source: ANN)