The 'baddies' in the religion/game known as
Elite.
Thargoid ships look like limpets, and have a nasty tendency to ambush you in hyperspace just when:
a) your cargo hold is full of easily breakable stuff (35 tons of eggs, say)
or
b) you have very little fuel left, and are on the run from a squadron of pissed-off police Viper crews who are blockading the local star and Coriolis space station (the only sources of fuel in the game).
Thargoids then proceed (usaually with the help of 3 or 4 cronies) to blow big holes out of your hull, destroying most of your profit.
They have (at least) two other annoying features:
1) they drop 'babies' - small tetrahedrons armed with laser cannon. These could be picked up and sold as 'Alien Items' (which gives you a wierd kind of pleasure: "Ha - eat plutonium death, you disgusting alien wierdos.... oh, and I'm selling your offspring into slavery when I reach Zades..."), were it not for a) above.
2) their ships are fitted with ECM devices, so missiles aren't an easy way out. However, ECMs take time to operate, which allows you to get a missile lock, nosedive the craft and drop a missile at the last possible moment.
2) above was in itself a great reason to play Elite, if only for the fact that flying through an expanding cloud of (admittedly pixellated) enemy ship fragments made you feel like
Starbuck out of
Battlestar Galactica.