Bhagavad Gita, Chapter 14, Verse 15

Meeting death in Rajas he is born among those attached to action; so dying in Tamas, he is born in the wombs of the irrational.

The same real principle is carried further here, down to a genuinely difficult outcome, birth among animals.

Krishna doesn't soften the consequence of dying under ignorance's influence, he names it plainly. Real stakes are attached to which force actually holds sway in that final moment.