Golf Ball and Snowball have shown a major conflict throughout BFDI. Snowball hates Golf Ball due to her insulting him and his intelligence.
Episodes suggesting a conflict
In Take the Plunge: Part 2, Golf Ball told Snowball that his brain is small and Snowball pushed Golf Ball off a cliff and into the water.
In Bridge Crossing, Snowball remembers what happened in Take the Plunge: Part 2, and rages, catches her, and throws her off the bridge. Golf Ball sunk, possibly killing her.
In Power of Three, when Golf Ball is chosen to be on his team, Snowball screams "NO!" and continue to fight throuought the episode.