How to kill a Spiketor?
If you have a retribution rune equipped, they will deal damage to themselves as they hit you. This can destroy them, which gives you a chance to get gold just like killing any other enemy.
There is no way to actively damage them without a little self-sacrifice, unfortunately.
After some testing, it seems that the spiketors die if they have two consecutive bounces in a short amount of space travelled in the interval between them.
This would prevent situations where a spiketor is bouncing in a narrow pathway, preventing passage as the character model isn't small enough to fit through the space in the passageway that the spiketor isn't touching.