Ȥ

Z with hook, Ȥ (minuscule: ȥ) is a letter of the Latin script.

Z with hook in Doulos SIL

The Unicode standard notes "Middle High German" for the application of the grapheme, intended to represent the coronal fricative /s/ also transcribed as tailed z ⟨ʒ⟩. It is used in modern printings of Medieval German literature to indicate those cases of ⟨z⟩ pronounced as [s], ⟨ȥ⟩, modern German: ⟨s⟩, from ⟨z⟩ pronounced as /ts/, as is still the case in modern German; the manuscripts typically used ⟨s⟩ to represent /z/.