Otto in the Neverland Bus with Bart
Otto eating toxic plutonium.
Otto in the bowling alley
Otto in a button-down shirt
Otto at the Simpsons' house
Otto after falling off a trampoline
Otto talking to Bart Simpson
Otto driving the prison bus
Otto confronted by the police
Otto asking a stupid question
Otto helping Lisa practice for a spelling bee
Otto sees a sad and visibly hurt Bart sitting in the school bus.
Otto glaring at Mr. Burns and Smithers
Otto and his second unknown love interest kissing at Homer and Marge's bedroom while Homer is sleeping.