Monster tokens and face-down monsters are included for “White Magician Pikeru”’s effect.
Even if there are many monsters, “White Magician Pikeru” increases Life Points by 1 lump sum.
“White Magician Pikeru” includes itself in its effect.
If you resolve “White Magician Pikeru”’s effect and then in the same Standby Phase the number of monsters on the field increases, you don’t get additional Life Points.