Quick solution for Spikes

Well, yeah, if the hot glue spikes get hot, they're gonna melt, just like anything made out of hot glue.

I made the warheads on Ramhorn's missile packs using said method.

And the tiny skulls on the shield for this figure (you can also see the skull mold I made to do it with in the process photos).

I've done other stuff too, but I can't recall what offhand.

and you don't have to worry about hot glue melting? I will have to try that..

I don't think this would work too well if you need the spikes to be pretty small, or rigid/sharp, but this might do:

#1: Find/secure or sculpt a single spike that is the right size.

#2: Roll out some Play-doh/clay, etc., deeper than the spike is long.

#3: Stick your spike into the clay multiple times, trying to obtain the same depth each time.

#4: Using a hot glue gun, inject hot glue into all of the depressions (this probably won't work well if your spikes are too small/narrow, unless you've got some kind of high pressure glue gun).

#5: Remove the spikes as soon as the glue hardens. Depending on what kind of clay you used, some of it might have adhered to the spikes, so wash 'em off with water.

#6: Presto, a bunch of spikes, quickly. Glue 'em on to your figure and paint. And, as an added benefit, cuz they're made out of hot glue, they should be relatively soft and child safe. I've used this technique to make skulls, missile warheads, etc. in the past.

I used spikes from a dog collar on my last one they're quite small but I think you can get bigger ones. I've used the bottom bits of birthday cake candle holders too