When local rockers the Boys from the County Hell first got together in the late '90s as a Pogues cover band, they were just supposed to play once and call it a day. But after selling out their first show at the now-shuttered Euclid Tavern, the group's popularity escalated, and it’s been going strong ever since. The group has performed in Las Vegas and in Thailand. The group plays its annual holiday show tonight at 7 at House of Blues.