I have noticed that some pets who have dmg reduction as one of their passive abilities doesn't proc dmg reduction, but instead proc armor reduction (red armor icon) while it's not supposed to even be part of their passive abilities.

Some of these pets are Koko, Kettle, Wrathjaw, Snaggletooth, etc. Other passive abilities of the aforementioned pets seem to work fine This bug doesn't seem to occur in Ribbit, Slag and Nexus' passive abilities as they always seem to proc dmg reduction (red dmg icon).