厶

si

private; snout

a slightly opened chest where one keeps private stuffs

鬼

gui

ghost, spirit of the dead

evil, demonic figure

The "head" (later stylized as 田 + 丿) was oversized, emphasizing supernatural power, now is stylized mask; 

儿 (legs) suggested floating or disjointed movement, added 厶 (private) symbolizes the hidden, elusive nature of ghosts

畏

wei

to fear, to dread;

awe-inspiring

Symbolizes a person wearing a devil’s mask (甶), while the kneeling figure below captures a human who is in fear

喂

wei

hello, hey

telephone greeting

to feed

喂奶 "to breastfeed"

Signifies calling (口) out to someone – Hello? Anyone? – in fear (畏) when walking about at night and feeling something eerie.

 The "feeding" meaning likely extended from vocal encouragement during feeding

Devil's Head

is not a standalone character;

This specific combo is unique to 鬼 and its derivatives