The 26-year-old Perpignan star is well aware of Scotland's strengths but is eager for his side to take another step towards a possible Grand Slam after their thrilling last-minute 23-21 win against Ireland on Sunday.
"Scotland will be tough opponents after losing to England," he said. "They will have something to prove, so we've got to beware of that.
"But I definitely think there's more to come from us and we'll be looking for improvements.
"After the way the boys performed in the World Cup, everyone realises we've got to step up and not just settle for being good players. We want to kick on and better ourselves."
Centre Jamie Roberts repeated Hook's concerns and insisted Wales would take Scotland very seriously considering the growing list of injuries to Warren Gatland's side - with forwards Matthew Rees, Luke Charteris, Alun Wyn Jones and Dan Lydiate all missing from the Aviva Stadium clash.
"We will definitely face a wounded animal in Scotland," added Roberts.
"They deserved to beat England and they will be coming to the Millennium Stadium looking to exact revenge.
"Those two words [Grand Slam] will be uttered during this week but we are week-by-week in this tournament; you can't afford to look too far ahead.
"We'll just rest up this week, prepare the bodies, get the minds right and same again from us hopefully."