Punctuate is a common Instant card from Unhinged (UNH), collector number 84. Current market price: $0.16 (foil $9.95), TCGplayer market prices via Scryfall.
Punctuate deals damage to target creature equal to half the number of punctuation marks in that creature's text box. (The punctuation marks are ! ? , ; : - — ( ) / " " ' ' & .)