Mathjax Arrow
\to \gets \rightarrow \leftarrow \Rightarrow \Leftarrow \mapsto \implies \impliedby \iff
→, ←, →, ←, ⇒, ⇐, ↦, ⟹, ⟸, ⟺
Ugliest Unicorn
\to \gets \rightarrow \leftarrow \Rightarrow \Leftarrow \mapsto \implies \impliedby \iff
→, ←, →, ←, ⇒, ⇐, ↦, ⟹, ⟸, ⟺