in RBY battles, when an opponent uses Mimic and then uses all four moves, the Zorua/Zoroark message shows up on the hover text. Example: I was playing Randbats against an opposing Jynx that knew Blizzard, Psychic, Lovely Kiss, Mimic and it Mimic'd Recover. So the hover text looked like:
Blizzard (6/8)
Psychic (whatever/whatever)
Lovely Kiss (whatever/whatever)
Mimic (15/16)
Recover (whatever/whatever)
"5 moves is usually indicative of Zorua/Zoroark" (whatever this message is)
I get why both Mimic and the Mimic'd move are listed in the 'mon's moveset but it triggers the Zorua/Zoroark message which I don't think should be there for pre-gen 5 games
(sorry I promise I'll start saving replays for this stuff in the future)
EDIT: Here's a replay, as requested:
https://replay.pokemonshowdown.com/gen1ou-1202314589
EDIT2: While I'm here, can't believe I didn't notice this before: in RBY battles the hover text for Psychic says 30% chance to lower Sp. Def, instead of 30% to lower Special
BUG STATUS: FIXED by DaWoblefet (Mimic/Illusion) and Karthik99999 (oldgen description)