Tahm Kench eating a minion bug.
When tahm kench eats a minion that is being focused by the tower, the current turret shot that is traveling to that minion will still hit and possibly kill the minion. Then, after, Tahm will then still do the spit-out animation, he will spit out nothing because the minion died to the tower shot.
It can be seen in the video above at 10:35.
This bug has a 100% reproduce rate if you try eat a minion that currently has a turret shot traveling toward it.
It is a bug that is small, but can really mess you up when trying to last hit under tower. As a Tahm Kench main, this can get quite annoying.
Thanks. If you have any questions, please don't hesitate to ask.