Create a Custom Object
Click Admin, and in the tree, select Database Management > Marketo Custom Objects.
Click New Custom Object.
Enter a display name. The API Name and Plural Name populate automatically, but you can edit them. Enter a description (optional).
Slide the Show in Lead Detail to display Show if you want to view custom object data on the Lead Database page. Click Save.
The custom object information displays the information you entered. Notice that it's in a Draft state. The next step is for you to build out your custom object. Click the link below to do that.