Most likely The Great Drunkard
These are the Walking Statues of Waterdeep:
- The God Catcher
- The Griffon
- The Sahuagin Humbled
- The Great Drunkard
- The Lady Dreaming
- The Honorable Knight
- The Hawkman
- The Swordmaiden
We can immediately rule some of these out by their descriptions or by images already presented in Waterdeep: Dragon Heist, leaving us with:
The God Catcher Image doesn't match
The Griffon Not a griffon
The Sahuagin Humbled Not a Sahuagin
- The Great Drunkard
The Lady Dreaming Not a lady
The Honorable Knight Not a knight in plate with sword and shield
The Hawkman Not a hawk man
The Swordmaiden Not a swordmaiden
Process of elimination yields The Great Drunkard. It's description gives some support as well:
This walking statue stopped its rampage as it approached the Market, then fell backward and sat upon a building. When it settled, its arms fell limp at its sides and its head tilted forward onto its chest, giving the impression that it had fallen asleep.
While the arms aren't limp at the side, it does have the tilting head. And at the end of the day, this is just an artist's depiction of...something. Of the available options, this one is the only one that comes close.