This document discusses 5 ways to build a $100 million SaaS company by focusing on different types of "animals" that represent average revenue per account (ARPA). It analyzes the ARPA of 74 SaaS companies at or around their IPOs and groups them into categories like mice (<$333 ARPA), rabbits ($333-$3,333 ARPA), deer ($3,333-$33,000 ARPA) and whales (> $333,000 ARPA). Most $100M+ SaaS companies target deer or elephants. However, some companies broke the rules to succeed with lower ARPA through viral growth, content/WOM, patience or moving upmarket over time. The key takeaw