North West, 52.45591,1.43366
Closed: before 1840
73 Earsham St
grid reference TM 333 897
This building is not shown as a pub on any available OS map (back as far as 1885), so probably closed a long time ago. Even in 1885, the adjacent bridge is called "Cock Bridge", but the building is marked as "Bridge House". It's identified as the former Cock in the Listed Buildings Register.
Cock fighting (usually in a pit) was probably a regular feature near here (typically organised on Shrove Tuesday and other holidays), and hence the name was widespread until it was banned in 1795.
(Most pub, location & historic details collated by Nigel, Tony or Keith - original sources are credited)