His first appearance is "Inoculation Day", he was shown among with Nika Kangaroo, Jim Warthog and the rest of his gang because he was afraid of shots and when he was shown outside reading a book he can be seen ran out of Adam's way when he was knocked over along with Steven Rhinoceros.
In "Shark Attack", we learned that Nerdly was afraid of Bull Sharkowski. He doesn't like to be bullied or get hurt as shown in the episode after, where he got hurt by Adam and Jake by playing the role of Jungle Guy and after he was disguised as a lady, he was Henry's cousin. Only in "Me Adam, You Jake"
But, however, in the episode "A Very Special Boy", he was redesigned and shown being kicked by Adam for no apparent reason. His braces are now gone, no longer speaks with lisp (much less sound nerdy) and was shown to be more aggressive than before.