The most difficult part of this design was actually getting the colors right. The rarest part is not, in fact, the chrome silver antenna, but the 8-long dark gray Technic axle. Generally, even-length Technic axles are black and odd-length axles are dark gray. The dark gray 8-long axle was included, so far as I can tell, in only one kit. And dark gray is the only color in which all the plunger parts are available. And this is the only plunger design I’ve come up with that satisfies me.

Here’s the parts list:

2 Plate 2 x 2 Round (#4032), Black

1 Plate 2 x 2 Round (#4032), Dark-Gray

1 Technic Axle 3 with Stud (#6587), Dark-Gray

1 Technic Axle 8 (#3707), Dark-Gray

1 Antenna 6H Chrome (#104), Silver

1 Bar 4L Light Sabre Blade (#30374), Trans-Red

2 Brick 2 x 2 Round (#3941), Trans-Red

1 Dish 2 x 2 Inverted (#4740), Trans-Red

1 Brick 1 x 1 Round with Hollow Stud (#3062B), Trans-White

6 Brick 2 x 2 Round (#3941), Trans-White

2 Plate 2 x 2 Round (#4032), Trans-White

1 Plate 2 x 4 (#3020), Trans-White

Anyway, if you don’t have the parts and want to build one, kits with Trans-Red elements for the “blood” version are available in my Etsy store. The model is fairly self-explanatory, but I have produced a simple set of instructions (PDF), which are visible below.