Any PC wearing the cowbell is affected per the notes on p 29 of the adventure. If they try to remove it, they must make a WIL save or be affected per the table on p 29.
The Office
Effects of consuming the Milk (may occur in other areas as well)
STR raises by 5 and WIL drops by 5 for 1d6 hours, make an STR save or the effects are permanent.
1) Entering the Basement
Cowbell alarm
Make a DEX save or set off the alarm
3) The Hallway
Scroll of Create Cow Beast
Create Cow Beast: Turns the target into a cow-beast abomination
Magic Dampener will temporarily dispel the effect of the arch, but the victim must make a WIL save every turn or revert to its cow form.
Effect Destroying of the Arch
Anyone present must make a WIL save or die. Succeeding on the save leaves them at 1 WIL until they recover.
9) The Beast
Daisy the Beast-Cow
9 HP, 2 Armor, 17 STR, 9 DEX, 8 WIL, fists (d8+d8) Heals 1d4 STR every 5 turns If the characters eat any meat from Daisy, make a STR save or have visions of her life for the next 2d6 weeks.