Doom and Gloom Mets Fan

The first fan to enthusiastically proclaim the Mets to be the best team in the league when they're on a hot streak then denounce them entirely when they hit a rough patch

Bob: "The Mets lost 6 in a row! They suck! They all suck! Even deGrom!"
Tom: "Weren't you just saying that deGoat and the Polar Bear were going to bring the Mets to a World Series championship like last week? You doom and gloom Mets fan."