The wiry, indignant and off-kilter leader of his clan, Lord Macintosh is always a heartbeat away from hysterics. His savage smile and fierce appearance – body bedecked in blue war paint and chest pridefully puffed up – proclaim that he’s ready for battle at any moment, though his bark may be worse than his bite.
Lord Macintosh arrived to King Fergus' castle along his clan, Clan Dingwall and Clan MacGuffin. When they arrived Lord Macintosh was the first one to present his son and candidate for Merida's husband.
When Lord Dingwall presented his only son, he started to make fun of him and so he got attacked by Wee Dingwall. He and his clan were fighting Clan MacGuffin, Clan Dingwall and Clan Dumbroh. However when Queen Elinor stopped the fight he started to appoligze along with King Fergus, Lord Dingwall and Lord MacGuffin. When the competition began his son almost succeeded and he was proud of that, however he was disappointed when Wee Dingwall won.
When Merrida started to compete for her own hand, he was shocked as well as King Fergus, Lord Dingwall and Lord MacGuffin. He was watching King Fergus' show and after King Fergus learned that there's a bear in his castle he was helping him until he got locked outside in a tower. After Merida and Queen Elinor returned to King Fergus' castle, Lord Macintosh and his clan were fighting Clan MacGuffin, Clan Dingwall and Clan Dumbroh until Merida stopped the fight and reminded the lords what they have been doing for each other, and solved the marriage problem by telling the lords that their sons should choose their soulmates.
After that he helped King Fergus capture Queen Elinor (because he didn't know it was her), after Mor'du showed up he was fighting him with his clan and the other clans. After everything was over, Lord Macintosh returned to his castle with his clan.
The painted blue motifs Lord Macintosh bears follow a Pictish tradition. They were supposed to give protection from sword blades in battle, or strength against enemies. Mark Andrews said by making this they wanted to give a mark of respect to the ancestors of the Scots.
Macintosh's name might be an allusion to Apple's personal computers, also named Macintosh.