"occasionally appears" is correct and usable in written English. It can be used to describe when something happens infrequently or irregularly. For example: My neighbor occasionally appears on my porch to borrow a cup of sugar.
He occasionally appears in his own cartoons.
He occasionally appears at festivals... festivals like Latitude 2013.
Schutz occasionally appears baffled by her work — she tends to apologize for not explaining it better.
If intrusive counselorese occasionally appears, it is more than compensated for by Crutcher's trademark wordplay.
As a musical form the rigaudon occasionally appears in the suite; e.g., in Rameau's Suite in E Minor for harpsichord.
But then again, without the organizing principle of travel, the book might be as shapeless as it occasionally appears.
Herne is said to ride at night, especially during storms; he wears horns, rattles chains, blasts trees and cattle, and occasionally appears to mortals.
Being a terminologist, I care about word choice. Ludwig simply helps me pick the best words for any translation. Five stars!
Maria Pia Montoro
Terminologist and Q/A Analyst @ Translation Centre for the Bodies of the European Union