Ok, I only asked because it looks like it has been chewed on. Is it possible that crickets left overnight could have done it? Is there anything in his tank he could have got it caught under? Or perhaps something happened while he was outside of his tank?
Either way, the tail should be kept clean to prevent any infection. That damaged part will most likely die and fall off, but you want to make sure to keep it clean so it heals properly and no secondary complications arise.
If you can get some bedatine you can make a weak solution of that to soak the tail in. Aim for the color of a light tea.
Raw unpasturized honey can also be applied to it to fight off bacteria. Just make sure there is nothing in the tank that might want to nibble on some sweet honey.
Poor guy! Definitely try getting some raw, unpasteurized honey to put on the end there,
to keep it from getting infected.
It looks like he might have gotten it caught it under or between something?
Poor guy, it may be that he's chewing on it himself. There have been at least a few of those posted in the forums in the past couple of years. Very strange but it happens sometimes.