Jackal and Clyde. There's a quest where you meet someone with multiple personality disorder in Broken Valley, one is called Jackal and the other is called Clyde and you get to choose which one to kill by having a potion brewed for the one you wish to destroy which will leave the other the sole occupier of the body. When you ask how they got into this situation, they mention they found a note afterward with the last words being "two have become one", the before parts of the notes rhyme. It's obvious Bellegar - the rhyming wizard is responsible for this. He's responsible for many stuff going on in Broken Valley.
Oh and skeletons in the closet. Where farmer Jackson killed a man called Booth because he slept with his wife - in a cave nearby the farm, you can find a closet with a skeleton in and underneath is a note about how the farmer dug him up while he was drunk to dress him in his wife's clothes but when he realized what he was doing - probably put him in the closet. The quest about the murder is activated if you read the farmer's diary. It's funny to note that the quest is called "skeletons in the closet" and Booth's skeleton can actually be found in a closet.
There's more - many quests and their characters often intervene with other events in the game.
As for the killer bunny - Brave Sir Robin mentions killing 19 rabbits in his book but with no killer bunny showing up. The later pages of his book mention how he killed around 59 undead - which was his brother in law who was being brought back to life every time Robin killed him by none other than Bellegar.
You may also find sleeping travelers during your travel through Broken Valley. Read their thoughts and listen at the items they mention. Finding these items will wake them for their sleep where they will mention a rhyming wizard put them to sleep. Once again - Bellegar's doing. He's pretty much the running gag of the game and many troubles are down to him.
