Boulder was given a magic boulder when he saved a leprechaun's life before he was asked to join the Kinsmen. His other teammates included Teleplex, Rapscallion, Highlander,  Wee One and Dyke. The Kinsmen are suppose to be Ireland's version of the Avengers and their first field assignment was to escort a retired Interpol agent, Sean Cassidy for a much delayed debriefing. Teleplex monitored the Kinsmen from a helicopter while the rest of the operatives head towards the Cassidy residence where they are greeted by the Banshee's daughter, Siryn. The Kinsmen inexperience leads to their downfall when they allow Siryn out of their sight and she changes into her costume. Siryn wants the Kinsmen out of her home but Wee One informs the lass that the government wants information from her dad and they are not leaving without him. Boulder attempts to crush Siryn with his magic boulder as it increases in size as it rolls. Siryn was playing possum when she created a hole in the floor and hits the boulder with a sonic scream. The boulder fails to shrink as it heads back to its master and runs him over. Siryn makes quick work of the Kinsmen and puts all of them out of commission.

Creation

Boulder was created by Scott Lobdell and Larry Stroman in 1990 and first appeared in Marvel Comics Present # 43.     

Powers & Abilities

Boulder possesses a magic boulder he can control and make it roll on its own. The boulder will increase in size as it keeps rolling towards an enemy and decreases in size when it comes back to its master.