Wikipedia:Articles for deletion/Hudson River Monster
I added another reference, but particularly note ''American Myths, Legends, and Tall Tales: An Encyclopedia of American Folklore'': it's an academic encyclopaedia that managed to sustain a fairly substantial entry on this subject, so there's no reason why Wikipedia can't manage the same. Overall, I think the sources cited meet the 'significant coverage' required by 
— User:Alarichall, 22:56, 20 March 2019 (UTC)
Stance: keep
Cited policy: WP:GNG (Wikipedia:Notability)