Volo’s Guide to Monsters 5-2=3
Xanathar’s Guide to Everything 35
Tasha’s Cauldron of Everything 21 Mordenkainen Presents: Monsters of the Multiverse 12+1=13
Volo’s Guide to Monsters 1
Xanathar’s Guide to Everything 34 Tasha’s Cauldron of Everything 21+1=22
Mordenkainen Presents: Monsters of the Multiverse 13-2=11
Volo’s Guide to Monsters 1 - 2 = -1 (I can't resist my second kill )
Xanathar’s Guide to Everything 34 Tasha’s Cauldron of Everything 22 + 1 = 23
Mordenkainen Presents: Monsters of the Multiverse 11