|They even copied the artwork straight from this creepy-looking toy.|
The Owlephant has the dubious honour of being one of the more disturbing.
Because otherwise, you'd have this.
|Fuck the police.|
And squid are horrible too - the Humbolt is known to attack humans, not for food or territory, just for fun. And scientists believe that they might only experience one emotion - rage. Not even kidding, folks... (I can only guess they recorded an attack, and could hear their Lovecraftian tentacle-faced giggles and screams all the way through...)
And finally, the ever-feared...
While the human-animal mixes are way more common, they're too "standard" to warrant a mention here.
Although, because I can never resist a wee dig at 3.5's sheer lack of balance, check out Savage Species' Anthropomorphic Animal templates. The Anthro Ape gets +2 Strength, +6 Dexterity, and +4 Wisdom, as well as +3 Natural Armour, with no penalties, for +0LA and 2 RHD. Then take the Tiefling: +2 Dex and Int, -2 Cha, Darkvision, a few resistances, and Darkness 1/day, for +1LA.
People are seriously not thinking these things through.
Anyway, back on topic.
Part of their appeal is that they can easily stock up any number of encounters - from a mad wizard's tower, to roaming free and on Random Encounter tables, to the bizarre effects of a spell gone awry, to summoned beasties from some nightmarish realm... the list goes on. And the humble Owlbear has probably ended more parties than any other creature in its level range. They're tough, dangerous, and angry at even existing.
Much like myself.
For a far funnier (and more in-depth) look at some of D&D's weirder monsters, go check out Dungeons and Dragons: Celebrating 30 years of Very Stupid Monsters (and Part 2) and the rest of Head Injury Theatre. The man has a great skill at cartooning, and his mad art skillz have inspired quite a few Risus seeds in my brain.