The scouts mother is a very especial class that can not be damaged by the spy
if in contact of a enemy spy for 2 minutes the scouts mother passive ability activates which give a timer for 9 months and after which a baby scout pops out on the battle field leaving the scouts mother at 1 hp and the baby scout starting with 25

the baby scout has one weakness a load of lead to the head causing the scout to die
and the scouts mother left at 1 hp can be killed by anything but the spy

(added in the great team fortress 2 comeback of 2026