Silicone toys come in lots of different firmnesses. Some are very rigid, and some are flexible and squishy. I don't have a lot of silicone dildos so I'm having a hard time thinking of examples for that.

A lot of my silicone vibrators (like my Lelos, Jimmyjane Forms, and MiMi)are made of a thin layer of silicone over a hard interior, so they are very firm. My Fun Factory Yooo and Spring have a much thicker, softer layer of silicone and are pretty squishy. less

Most silicone toys, even if they're not squishy, are quite capable of bending. The only exception I've come across personally is the Ella. LELO's Ella is extremely firm, and I've heard that this is true for most LELO toys. The Ella's "neck" can move, but that's it.

The firmness of Tantus silicone seems to depend on how thick it is. The Charmer, Silk Medium, and the shaft of the Acute are all pretty squishy. On the other hand, the Acute's head and the Silk Large, while still having some give, are feel firmer because they are thicker. Fun Factory stuff tends to be fairly soft (though not O2 or VixSkin soft).

One of the most interesting examples is Bad Dragon silicone. While the toys themselves may not be everyone's cup of tea, they are ahead of the curve when it comes to customization. Their silicone comes in three different levels of firmness, and you can choose whichever you like best when ordering. less