Bluster is a bulldog who appears in the cartoon show episode "Sideshow Smurfs". He travels around on a wagon with his master Bombast, who is very harsh toward his performers, including his dog, who was at one time Bombast's main star attraction.
In the episode, Bluster came across Clumsy and Smurfette as they fell down into a hole, so Bombast took them out of the hole and put them in a cage in his wagon, believing that they will make fine performers as he trained them in various acts before presenting them to the humans in a nearby village. Bluster was rather jealous that his master was more interested in the new performers, but Bombast prevented him from doing any harm to them through the use of threats. Bluster was lured into helping Clumsy and Smurfette escape from their cage in Bombast's wagon, but they didn't get far in their escape when they wound up in Bombast's nail sack and were returned only to be captured again.
However, on the day the two Smurfs were supposed to perform, it had started to rain over the human village, which meant that nobody will come out to watch the two Smurfs perform -- until he saw Gargamel walking out in the rain with his cat Azrael. Gargamel spotted the two Smurfs in Bombast's wagon and offered to pay the showmaster money in exchange for them, but Bombast wasn't willing to part with his performers. When Gargamel tried to steal the Smurfs from the wagon, Bluster had stopped him from getting far with his stolen prize.
By the end of the story, Bluster was with his master Bombast chasing Gargamel and Azrael through the forest, threatening to get his payment from their hides after Papa Smurf and the other Smurfs had taken Clumsy and Smurfette safely away.