It looks to me like it's essentially a strip of marabou feathers glued into the slot of the helmet. You could probably buy a marabou feather boa from a costuming store and piece it down to what you'll need- you could even combine colors to get the yellow-orangey red coloring Cyndiquil has.
Klan Klang (Lovely Bomber) - Macross Frontier: SnT - (15%- Sewing and logistics)
Jam Kuradoberi - Guilty Gear - (95%- new wig+touchups)
Youmacon '12 My Curecos My ACP My dA