A dog wearing undies on his head for a Boost Juice Undy Monday Facebook campaign proved such a success that he was given his own social media  promotion by the juice bar franchise.

‘Alan’s Christmas Bark in the Park’ campaign called for Facebook followers to tell Boost in 25 words or less the ideal ingredients for a smoothie for Alan the dog.

Four respondents have each won twin share flights to Sydney to meet the popular pooch on Saturday 1 December for an afternoon picnic.

However, not everyone proved to be a fan of the four-legged brand ambassador. One comment read “Why would I want to meet an overgrown rat?”

• Boost Juice is part of the Retail Zoo group.