flatcallers are whales, like call ATC
3bshover is a 13/7 but only over 45 hands so I don't know if he's a nit just yet, but it's very possible

could he be valueshoving to get called by the fish?
Full Tilt No-Limit Hold'em, $1.00 BB (6 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

MP ($63.90)
CO ($106.55)
Button ($141.60)
SB ($120.35)
BB ($122.35)
Hero (UTG) ($136.65)

Preflop: Hero is UTG with Q, Q
Hero bets $4, MP calls $4, CO calls $4, 2 folds, BB raises to $122.35 (All-In), Hero?