Welcome to Librarium Online!
Not too familiar with nids..
If I give a tyrant a cannon and talons, does the extra attack contribute to the number of shots I fire?
no it only adds an attack in combat. A venom cannon is not very good for a Tyrant any way. The Tyrant is isn't strong enough to use it properly. Consider devourers or duel scything talons.
Acually, a tyrant with enhanced senses, toxin sac and a venom cannon has the same statistical glance-rate against moveing A12 scimmers that 2 carnifexes with venom cannons do between them. Seeing as A12 scimmers are a rather huge threath any tyranid army I can think of, I wouldn't quite call venom cannon a poor choise for a hive tyrant. It's expensive tho..
Tyranid codex page 31 - under close ranged biomorphs. It's all there. ^__^
LO RulesOriginally Posted by AnonymousOriginally Posted by Cyric