Ybur held the book in his arms, his mind churning with thoughts.
Multi-headed Snake Lizards have a special ability called "Multiple Minds."
Not only Multi-headed Snake Lizards, but creatures like Two-headed Giants and two-headed ogres possess similar abilities—multiple consciousnesses and brains operating simultaneously within a single body. On one hand, this leads to frequent conflicts between the multiple minds, causing self-confusion for these creatures. On the other hand, however, it also means that… when facing mental control spells, these creatures have a stronger resistance.
Multiple minds can "share" the effects of mental control; if the spell targets only a single mind, it might even result in a situation where "one is controlled, and the other remains clear-headed." Although internal strife might still occur, it's much better than having both minds controlled…