Wizard's 'Massive Head' Spell – Massive heads, small facial features.

If you want to make heads look inflated; just use something like massive head orbig head with small facial features,
You can preface your prompt with1nfl4t3d_h34d. which might help with more stubborn cases, but it's not necessary.

LoRA Strength: 1.0 as a start, go down to 0.8if it's too same-facey for your liking, just compensate with more descriptions like enormous/giant