Mottle is a custom chatbot creation tool that allows users to build expressive ChatGPT-like chatbots using their own data. By simply dragging and dropping files such as .pdf, .doc, .docx, or .txt onto the "Train Your Bot" page, users can create bots for purposes like customer service or internal knowledge. Mottle uses OpenAI's ChatGPT to construct answers based on the provided data, ensuring responses are limited to the information given. This makes it crucial for users to provide high-quality information to create effective chatbots. Once the bot is trained, it can be shared via API or embedded on a website. Mottle offers a free plan and paid tiers to accommodate various user needs.