Mirrorweave

Each other creature copies the printed values of the targeted creature, plus any copy effects that have been applied to that creature. They won’t copy other effects that have changed the targeted creature’s power, toughness, types, color, or so on. They also won’t copy counters on the targeted creature (they’ll each just retain the counters they already have).

If the targeted creature is a token, each other creature copies the original characteristics of that token as stated by the effect that put it onto the battlefield. Those creatures don’t become tokens.

Noncopy effects that have already applied to the other creatures will continue to apply to them. For example, if Giant Growth had given one of them +3/+3 earlier in the turn, then Mirrorweave made it a copy of Grizzly Bears, it will be a 5/5 Grizzly Bears.