Will flip upside-down when Isaac tries to collect it. Afterwards, it will get stuck on the ground, unable to be picked up unless blasted off the ground with an explosion. Bumbo and Bum Friend are unable to pick this up; they instead hover over them, attempting to pick them up.
During the Ultra Greed fight, if a Sticky Nickel drops, Ultra Greed will be continuously drawn to it.
Sticky Nickels visibly stick to the ground upon spawning, making them easier to distinguish from ordinary nickels.
In the unlikely event that a Sticky Nickel is present during the Bumbino fight, the boss will try to pick the coin up in futility, making him distracted and thus negating much of the difficulty of the fight.
Sack Head can cause Golden Penny to spawn a sack instead of another golden penny.