Copyright and trademark

The silhouettes of current (or reasonably current) famous figures are almost certainly protected by copyright law (as original graphic creations) and/or trademarks (as symbols used to identify the business). That fact that it is a silhoutte, rather than a front view or a color picture, does not diminish the protection: essentially, if the thing is copyrighted and/or trademarked (which it almost certainly is, if it is a famous, and hence valuable, character) and the silhoutte is recognizable (which is the only reason you would be doing this), then you are violating their intellectual property.
Remember: both copyright and trademark give the rights holder the exclusive right to create modify the original property or create derivative works based on it (copyright) or to market using a recognizable expression of that logo, image, etc. (trademark).
As to fonts: you most likely cannot use that font for the name of the character, since it very likely that, for a famous character or property, that the combination of name plus the font they always use is trademarked; but you could use the font other than for the name. Take "Star Wars": "Star Wars" in the font they always use is very recognizable and is part of their trademark. But you could use the "Star Wars" font for (or example) "Bob's Pizza Kitchen" without liability.