SpongeBob is a sea sponge , but he resembles a kitchen sponge , being rectangular and bright yellow . In the previous episode , he is wider near the top and slim down , but in the newer episodes , he is a regular square . SpongeBob has large blue eyes , short nose , large mouth with prominent front teeth , and dimples with three freckles on each cheek . He usually wears a white shirt with a red tie , black leather shoes with shoelaces , and brown rectangular pants with a black belt ( the entire outfit is sometimes called " pants " ) . While working at the Krusty Krab , he wears a hat , tall white with a small blue anchor on it as a uniform . SpongeBob sleeping with street clothes on top , including shoes. Although SpongeBob has always voiced by Tom Kenny, the voice has changed over the series , his voice lower than usual in the pilot episode , and after the movie , the sound will be a little higher pitched .
SpongeBob is a character that is not able to understand , mature , and hyperactivity . He is a very determined person , and will often stop at nothing to complete the task . He is also somewhat dramatic to people who kind to him , for example , for the postman . He was also very over-confident and sometimes exaggerate problems , such as losing his ID .
SpongeBob is very kind-hearted and plain , and very rarely acts openly to anyone , even his enemies . He is a very altruistic and loyal , especially to those close to him . Selfishness of others shown in the episode " Best Day Ever " , in which he gives " perfect day " was to help his friends . Despite good intentions , SpongeBob actions often interfere and cause problems for the people around him , especially the next-door neighbor , Squidward Tentacles .
SpongeBob error also makes him overly trusting and very gullible, and he is easily manipulated by those who intend to use and / or harm him , such as Squidward , Mr. . Krabs and Plankton ; The most obvious , he is always easily fooled by Plankton no matter how bizarre or obvious disguise . Although it is generally good-natured and relaxed , when frustrated and angry , SpongeBob can be sarcastic , rude and ' foul-mouthed ' to his friends , even Mr . Krabs , whom he treats as a father . Funny thing is , Squidward is the only character who never insulted SpongeBob when cheated , he sometimes still believe even though Squidward already confessed .