Mistwell
Crusty Old Meatwad
That sounds like WAY more work than is needed. Prep a card? Sheesh.
"You see a Squamous Thing."
"I roll 25 on my Arcana check."
"OK, the Squamous Thing is vulnerable to acid and can eat your spleen from 20 feet away."
"Cool."
I can't imagine it being a difficult or complex process. Hell, 4e -- the game under discussion -- even tells you EXACTLY what you know with each level of knowledge check.
I said prep because not all players should know the info.
Its VERY little time to make a card of that info in 4e. But if its not your thing, its still faster to say that info every time than role and look it up on a chart each encounter.