Terrible terrible tethracross

The terrible terrible tethracross is equal to E100((#^^##)^^#)^^#100 using Extended Cascading-E Notation. The term was coined by Sbiis Saibian.
== Approximations in other notations ==
Notation 	Approximation
BEAF 	(X^^^X)^^(X+2) & 100
Bird's array notation 	\(\{100,100[1 \backslash 3 \backslash 2]2\}\)
Fast-growing hierarchy	\(f_{\varepsilon_{\zeta_0+2}}(100)\)
Hardy hierarchy 	\(H_{\varepsilon_{\zeta_0+2}}(100)\)
Slow-growing hierarchy	???
== Sources ==
Category:Numbers
Category:Numbers by Sbiis Saibian
Category:Extended Cascading-E numbers
Category:Binary phi level
Category:Tethracross regiment