immortal bot glitch

i was playing for a few minutes killing some noobz and then i saw some bot cheasing me so i tried to kill him but i didnt hit him. i tried many times but it was impossible to kill it. i tried with explosives and quicksands but he just walked on them like jesus on water. its second tie i see this glitch so its probably very rare but its really annoying when you need to run all the time and wait for another person to be the king.[he cheased only me when i was the king]