Edits: tail, mane, horns, eyes
Glass, color changing
Basic form, transparent background

Hex Codes:
#d4fef1
#cafeee
#e4fff8
#093f47
#1b626c
#3bbdd2
#f7ceef
#ffffff
#525252
#474747
Basic form, background

Blue/green fill

#d4fef1
#cafeee
#e4fff8
#093f47
#1b626c
#3bbdd2
#f7ceef
#ffffff
#525252
#474747
#4868ec
#67dde2
#4bd8a5
#49ee80
#6df054
#d2f14f
#e4d158
#e0bc5c
Red fill

Hex Codes:
#d4fef1
#cafeee
#e4fff8
#093f47
#1b626c
#3bbdd2
#f7ceef
#ffffff
#525252
#474747
#4e0909
#c4091b
#ff0c1a
#9b0917
Halloween costume

For drawing him: his basic form is a dark gray body with transparent very pale blue for his horns, tail, hair, paws/hooves, and body glass. You can have creative liberty for whatever color you want to fill these in (or not)!
(Basic, semi-transparent form)
Glass
#cbfff0
#eafff9
Eyes
#093f47
#1f90a2
#3dc2d7
#f9d0f1
Body
#525252