Yeah I tried givving it claws as for a ling, but it didn't work(used DatEdit). Any ideas how to do this so that the scantid will attack? I don't wanna make animations for this. It could be even still.

You have to add an attacking animation in the scantid's iscript entry.

And, just to note, if your scantid is owned by player 12, it won't attack.

Add strings in IScript ScantidGndAttckInit, ScantidGndAttkRpt & ScantidGndAttktoIdle. You may use existing frames of scantid to make it attack (it may even play one frame looped, altough it may look silly). The same for other creatures. If you want it to range attack write use command attack25, if melee attack1c (however if you are going to give melee attack to Kakaru it needs set ground melee weapon too, otherwise it won't work. If you don't want it to melee attack ground, while still possessing Air melee attacks you'll have to direct CreatureGndAttkInit direct to null i.e. CreatureIdle or CreatureOther)

So how do I do this kind of things using DatEdit ? I 'd like to hear the easiest way to do this, while having an animation that'd show the player that he's under attack.

"So how do I do this kind of things using DatEdit ?"
You don't. =P
You use ICE or IceCC.
There is one option for making it work using only DatEdit, but it's rather crude. Simply, try changing its animation to use other units' iscripts. Eventually, you may find one that works. ;P It almost certainly won't look too great, however, and the great majority of units will crash. It's far, far more advisable to just learn to iscript, if possible.
Unless you want to try making yourself distinguished as the person making the most innovative graphics changing without iscript. xP