https://minecraft.fandom.com/wiki/Minecraft_Dungeons:Evoker#Vex

Appearance A vex's appearance in Dungeons is almost the same as its original appearance in the base game, with the only difference is it being more luminescent and glowing unlike its normal, default counterparts, as well as having darker colored cracks on its skin and shorter wings. Another key difference is that when attacking, the cracks now appear as a flaming orange rather than white.

Behaviour There is no limit to the number of vexes following the hero. Vexes are also the only other entity in the game that can roll, besides dead mobs and Redstone cubes. They can only roll while attacking or idle.

thanks, Carlos_33 and sans is justified and punny for the design of the charged vex made...