I ran into a strange bug when facing Muggy in the current Raid Tournament (3*, buff booster).
When killing an enemy with Muggy’s buff active, he will revive as himself instead of as a chameleon.
This seemed to have no effect on the special - I can’t recall if Muggy’s “Fierce Slash” affects all enemies as it did in the videos - so I think this is only visual, nevertheless confusing. Sorry if this was known already.
Unfortunately I forgot to check the hero stats to see if they also changed when reviving.
Edit : I just saw this topic [SOLVED - V 35.1] Muggy's skill doesn't work properly, heroes revive but since mine seems somewhat different I’ll leave it up to the mods to decide if they should merge or delete.