A fan mode is a more obscure term in the fandom. It is basically any configuration of a Transformers toy not meant as an official configuration or alluded to in anyway.
It is important to exercise caution when attempting to create (discover?) fan modes, because it might be hard to revert the toy from them and you might break it in the process.
The fan mode also includes non-official Combiners, such as creating a Scramble City type Combiners from various Combiner team, or, creating a Combiner from characters who can't combined to each other. For example, using the Powere Core Combiners Mini-Cons to form a gestalt can be formed.
- Revenge of the Fallen Voyager Starscream/Nebular Starscream- Super jet mode (has X shaped wings)
- Hunt for the Decepticons Scout Insecticon- Halo Elite mode
- Revenge of the Fallen Legends Soundwave- Bat mode, Interstellar jet mode (like the 2007 Leader Megatron), Cybertronian Space Cruiser mode (from the Revenge of the Fallen game)
- Revenge of the Fallen Legends Megatron- Jet mode (poor resemblance to 2007 Megatron)
- Revenge of the Fallen Voyager Megatron- Jet mode (resemblance to 2007 Megatron)
- Revenge of the Fallen Voyager Mindwipe/Reveal the Shield Strafe- Mindstalker/Strafestalker (Mindwipe/Strafe and Skystalker, combined), Mindspot/Strafespot (Mindwipe/Strafe and Sunspot, who is a repaint of Skystalker, combined), Bat mode
- Dark of the Moon Deluxe Barricade- Stealth force mode
- Dark of the Moon Deluxe Sideswipe- Super mode