Board Thread:Support Requests - Designing Your Wiki/@comment-46227053-20200710183421/@comment-39340968-20200710183950

.ns-112 .wds-community-header__wordmark {background: url("https://images.wikia.nocookie.net/avatar/images/9/92/Avatar_Fanon_Wiki_Logo.png") no-repeat scroll 0% 0% transparent !important;} .ns-113 .wds-community-header__wordmark {background: url("https://images.wikia.nocookie.net/avatar/images/9/92/Avatar_Fanon_Wiki_Logo.png") no-repeat scroll 0% 0% transparent !important;} .ns-114 .wds-community-header__wordmark {background: url("https://images.wikia.nocookie.net/avatar/images/9/92/Avatar_TLA_Wiki_Logo_copy.png") no-repeat scroll 0% 0% transparent !important;} .ns-115 .wds-community-header__wordmark {background: url("https://images.wikia.nocookie.net/avatar/images/9/92/Avatar_TLA_Wiki_Logo_copy.png") no-repeat scroll 0% 0% transparent !important;}

This is what they used, make sure to replace the links that they have with the ones you want to use for your wiki.