。
I really can't stand reptiles.
Literal
Reptiles [subject-が] big-dislike [copula-(omitted)].
A short statement of strong aversion. 爬虫類 (はちゅうるい) is the formal biological term for 'reptile' — literally 'creeping insect class' (爬 'to creep', 虫 'bug', 類 'class'). 大嫌い (だいきらい) is 'strongly dislike/hate' — the intensifying prefix 大 attached to 嫌い ('disliked'). Note the missing copula at the end, casual.