Doctor Who: 5 Best & 5 Worst Creature Designs From The Original Series
Best Creature no 5: The Sontarans (The Time Warrior and others)
They may not be the most visually-striking but the Sontarans weren't a bad idea. It's easy to mock their appearance but it actually represents a refreshing change from most of the tentacle-waving bad guys that feature in a lot of Pertwee-Baker era episodes. Plus they don't speak in silly voices, which is always a plus. I'll agree that they aren't the most convincing of monsters in terms of their looks but they have a fairly extensive back story and are the only ones to admit the real reason as to why most Doctor Who monsters want to get rid of us humans: it's fun. Basically the Sontarans love war and want to win as many battles as possible for the honour of their race. Sounds shallow but it's clear they aren't mucking around (they even get a war-chant in Series 4: Sontar-ha!).
With so many monsters in Who it can be hard to make anything seem new, but I can't remember any alien being quite like the Sontarans. The three fingers on each hand are a subtly strange touch, and I believe in an episode of The Sarah Jane Adventures it was found that they had their own version of the decimal system, using threes. Their armour is practical and they definitely don't have to stoop through doorways, and there even appears to be a little evolution going on too (the tall Sontarans were definitely a bad idea) but my favourite thing about them has to be those golf ball spaceships. They are just so cool.