Manufactured Wurm

Manufactured Wurm has base power and
toughness X/X. It has trample if its power is 6 or greater.
Improvise (Your artifacts can help cast this spell.
Each artifact you tap after you're done activating
mana abilities pays for {1}.)
For each artifact that was tapped to cast Manufactured Wurm, put a +1/+1 counter on it.