i saw some maps that the animals or so called critters can attack and destroy units
can someone tell me what trigger does it mkake that
tell me this as soon as possible.
Critters cannot attack or destroy units. Please show me a screenshot or the map that does this. Then I can perhaps explain what you are talking about.
You make a 2x2 location, make it follow the critter everywhere, and trigger it so that the location kills units. End of topic

Or perhaps you were playing a MOD, not a map? You can this in mods, but they are not compatible across B.net