Their physiques made them very tough enemies to defeat, especially if you're playing Diddy Kong. If Diddy Kong tries to jump on them, they will laugh and continue walking. The only way to defeat them is to throw barrels at them or let Donkey Kong jump on them.
In the last level, before the final two bosses, brown Krushas appear and are even stronger than the blue ones. Donkey Kong is unable to harm them with his jumps, so the only thing that can harm them are barrels.
Krusha is also a character in the Donkey Kong Country TV series. He was voiced by Ron Rubin.