Bridge Trolls are a race of trolls seen in King's Quest: Adventures of Graham.
They are literal 'bridge trolls' in that are trolls that have a bridge growing out of their head and back. Many appear to be giants but it is rumored that there are smaller members of the species living in Llwedor.
There is also a specific species troll giants, known as Bridge Trolls. It is said that bridge trolls have a secret guild, the Bridge Troll Guild (there are two known guilds Llwedor Bridge Troll Guild, and the Daventry Bridge Troll Guild). These trolls will give free passage to anyone who has the proper mouthpieces to their horns. They also have a taste for goat, unlike most trolls.
There is no Bridge Troll Guild in Avalon (KQGS).