Matthias, Hero of Redwall

Haste
Whenever Matthias, Hero of Redwall and at least
one other creature attack, look at the top six cards
of your library. You may put a creature card from among them onto the battlefield tapped and attacking. Put the rest on the bottom of your library in a random order. Return that creature to
its owner's hand at the end of combat.
"One day Redwall and all the land will be indebted to you. Matthias, you are a true warrior."