Gertrude

Gertrude is an NPC in Varrock she is the quest start for Gertrude's cat and Ratcatchers quest. She will also sell you kittens (you can only have one kitten at a time) for 100gp and the colour of the kitten is random unless you have a Ring of Charos then you will charm Gertrude into letting you chose the colour of the kitten.