Weight: 2 lb.
Estimated Value: 450 gp
This hat has 3 charges. While holding the hat, you can use an action to expend 1 of its charges and speak a command word that summons your choice of a bat, a frog, or a rat. The summoned creature magically appears in the hat and tries to get away from you as quickly as possible. The creature is neither friendly nor hostile, and it isn't under your control. It behaves as an ordinary creature of its kind and disappears after 1 hour or when it drops to 0 hit points. The hat regains all expended charges daily at dawn.
Source: Xanathar's Guide to Everything p137