The three-toed sloth actually has four toes, one on each foot, but as they fall off regularly and are regrown, the typical sloth only has three toes at any one time.
The Coriolis Force is the reason why more left-handed people, per head of population, are found in the southern hemisphere than in the northern. (Darren: Sorry, your entry is now null and void - points will be deducted. Depending on how you read it, your statement is correct).
There are always seven Wonders of the World. If one is destroyed, an unranked Wonder ascends to the Seven. However, knowledge of which are the Seven Wonders was lost in the 16th century.
There will never be thirteen British monarchs with the same name, since it would unleash a constitutional crisis as to whether the last should be designated XIII or XIIb.
When attempting to produce a statement that could plausibly be true, but probably isn't, the probability that additional statements will enter outright lie territory rises in proportion to the 2.5th power of the number of statements made thus far.