What kind of spider looks like a big swollen up tick?

The spider that resembles a big swollen tick is likely the woodlouse spider (Dysdera crocata). It has a robust, rounded body and can appear swollen, especially when viewed from certain angles. Another possibility is the female black widow, which can have a similar shape but is usually much darker. Both Spiders have distinct features that set them apart from ticks, such as eight legs and different body segmentation.