Tahm Kench's devour fails to contain some (minion) units.

When Tahm attempts to devour some units (Zz'Rot minion, Yorick minions [NOT Maiden of the Mist], etc.) the minion will reappear behind Tahm's model and take no damage. Tahm's devour will go on full cooldown.

Recreation: Cast Tahm's devour on any of the aforementioned units (or similar; the list is not exhaustive).

This bug occurs with 100% success unless the ability is recasted immediately, at which point the ability functions normally. However, it should be noted that the workaround for this bug involves another bug:

When Tahm immediately recasts his devour while containing a minion-class unit, the resulting projectile will pass through walls.