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What's funny about the truck in reality is how out of place it is with the rest of the game, including from an aesthetical viewpoint
This is because it's a leftover sprite from the earliest builds of the game (the "Capsule Monster" era), either it's hardcoded in the game since is hasn't even been moved from the map or somebody on the team must have been very proud of the truck sprite that they couldn't just not use it, even if it's inaccessible in normal gameplay. And then a legend was born.