Variety reports that Tim Sullivan has been hired to pen Shrek 4, after the writer accepted an invitation to pitch his idea at DreamWorks. The news comes on the heels of the announcement that David H. Steinberg will write the Shrek 2-spinoff Puss in Boots. Meanwhile, Shrek 3, written by Peter Seaman and Jeffrey Price (the duo behind How the Grinch Stole Christmas), is nearing pre-production.