diff --git a/godot-core/src/builtin/quaternion.rs b/godot-core/src/builtin/quaternion.rs
index 446bf8148..fe5ddc23a 100644
--- a/godot-core/src/builtin/quaternion.rs
+++ b/godot-core/src/builtin/quaternion.rs
@@ -9,7 +9,7 @@ use godot_ffi as sys;
 use sys::{ffi_methods, GodotFfi};
 
 use crate::builtin::math::{ApproxEq, FloatExt, GlamConv, GlamType};
-use crate::builtin::{inner, real, Basis, EulerOrder, RQuat, Vector3};
+use crate::builtin::{inner, real, Basis, EulerOrder, RQuat, RealConv, Vector3};
 
 use std::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Neg, Sub, SubAssign};
 
@@ -30,10 +30,14 @@ impl Quaternion {
         Self { x, y, z, w }
     }
 
+    /// Creates a Quaternion from a Vector3 and an angle.
+    ///
+    /// # Panics
+    /// If the Vector3 is not normalized.
     pub fn from_angle_axis(axis: Vector3, angle: real) -> Self {
         let d = axis.length();
-        if d == 0.0 {
-            Self::new(0.0, 0.0, 0.0, 0.0)
+        if d != 1.0 {
+            panic!("Attempted to create a Quaternion from a Vector3 that was not normalized.");
         } else {
             let sin_angle = (angle * 0.5).sin();
             let cos_angle = (angle * 0.5).cos();
@@ -130,8 +134,16 @@ impl Quaternion {
         Quaternion::new(v.x, v.y, v.z, 0.0)
     }
 
+    /// Normalizes the Quaternion.
+    ///
+    /// # Panics
+    /// If the Quaternion has length of 0.
     pub fn normalized(self) -> Self {
-        self / self.length()
+        let length = self.length();
+        if length == 0.0 {
+            panic!("Attempted to normalize a Quaternion with 0 length.");
+        }
+        self / length
     }
 
     pub fn slerp(self, to: Self, weight: real) -> Self {
@@ -174,21 +186,73 @@ impl Quaternion {
         inv_factor * self + new_factor * to
     }
 
-    // pub fn spherical_cubic_interpolate(self, b: Self, pre_a: Self, post_b: Self, weight: real) -> Self {}
-    // TODO: Implement godot's function in Rust
-    /*
-        pub fn spherical_cubic_interpolate_in_time(
-            self,
-            b: Self,
-            pre_a: Self,
-            post_b: Self,
-            weight: real,
-            b_t: real,
-            pre_a_t: real,
-            post_b_t: real,
-        ) -> Self {
+    /// Performs spherical cubic interpolation.
+    ///
+    /// # Panics
+    /// If the provided Quaternions are not normalized.
+    pub fn spherical_cubic_interpolate(
+        self,
+        b: Self,
+        pre_a: Self,
+        post_b: Self,
+        weight: real,
+    ) -> Self {
+        let interpolated =
+            self.as_inner()
+                .spherical_cubic_interpolate(b, pre_a, post_b, weight.as_f64());
+        // Godot returns default if you give it Quaternions that are not normalized. This means we can check for default
+        // Then check if we should panic.
+        if interpolated == Quaternion::default()
+            && (!b.is_normalized()
+                || !pre_a.is_normalized()
+                || !post_b.is_normalized()
+                || !self.is_normalized())
+        {
+            panic!(
+                "Attempted spherical cubic interpolation on Quaternions that are not normalized."
+            );
+        }
+        interpolated
+    }
+
+    /// Performs spherical cubic interpolation in time.
+    ///
+    /// # Panics
+    /// If the provided Quaternions are not normalized.
+    #[allow(clippy::too_many_arguments)]
+    pub fn spherical_cubic_interpolate_in_time(
+        self,
+        b: Self,
+        pre_a: Self,
+        post_b: Self,
+        weight: real,
+        b_t: real,
+        pre_a_t: real,
+        post_b_t: real,
+    ) -> Self {
+        let interpolated = self.as_inner().spherical_cubic_interpolate_in_time(
+            b,
+            pre_a,
+            post_b,
+            weight.as_f64(),
+            b_t.as_f64(),
+            pre_a_t.as_f64(),
+            post_b_t.as_f64(),
+        );
+        // Godot returns default if you give it Quaternions that are not normalized. This means we can check for default
+        // Then check if we should panic.
+        if interpolated == Quaternion::default()
+            && (!b.is_normalized()
+                || !pre_a.is_normalized()
+                || !post_b.is_normalized()
+                || !self.is_normalized())
+        {
+            panic!(
+                "Attempted spherical cubic interpolation in time on Quaternions that are not normalized."
+            );
         }
-    */
+        interpolated
+    }
 
     #[doc(hidden)]
     pub fn as_inner(&self) -> inner::InnerQuaternion {
diff --git a/itest/rust/src/builtin_tests/geometry/quaternion_test.rs b/itest/rust/src/builtin_tests/geometry/quaternion_test.rs
index 9a1df447e..d8921a3b9 100644
--- a/itest/rust/src/builtin_tests/geometry/quaternion_test.rs
+++ b/itest/rust/src/builtin_tests/geometry/quaternion_test.rs
@@ -5,8 +5,9 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
-use crate::framework::itest;
-use godot::builtin::Quaternion;
+use crate::framework::{expect_panic, itest};
+use godot::builtin::math::assert_eq_approx;
+use godot::builtin::{Quaternion, Vector3};
 
 #[itest]
 fn quaternion_default() {
@@ -28,4 +29,79 @@ fn quaternion_from_xyzw() {
     assert_eq!(quat.w, 0.8924);
 }
 
+#[itest]
+fn quaternion_normalization() {
+    expect_panic("Attempted to normalize a Quaternion with 0 length.", || {
+        Quaternion::new(0.0, 0.0, 0.0, 0.0).normalized();
+    });
+    let quat = Quaternion::default();
+    assert_eq!(quat.normalized().length(), 1.0);
+}
+
+#[itest]
+fn quaternion_from_angle_axis() {
+    let quat = Quaternion::from_angle_axis(Vector3::new(0.0, 0.0, 1.0).normalized(), 1.0);
+
+    // Taken from doing this in GDScript.
+    assert_eq!(quat.x, 0.0);
+    assert_eq!(quat.y, 0.0);
+    assert_eq_approx!(quat.z, 0.479426);
+    assert_eq_approx!(quat.w, 0.877583);
+
+    expect_panic(
+        "Attempted to create a Quaternion from a Vector3 that was not normalized.",
+        || {
+            Quaternion::from_angle_axis(Vector3::new(0.0, 0.0, 0.0), 1.0);
+        },
+    );
+}
+
+#[itest]
+fn quaternion_spherical_cubic_interpolate() {
+    let pre_a = Quaternion::new(-1.0, -1.0, -1.0, -1.0);
+    let a = Quaternion::new(0.0, 0.0, 0.0, 1.0);
+    let b = Quaternion::new(0.0, 1.0, 0.0, 2.0);
+    let post_b = Quaternion::new(2.0, 2.0, 2.0, 2.0);
+
+    let outcome =
+        a.spherical_cubic_interpolate(b.normalized(), pre_a.normalized(), post_b.normalized(), 0.5);
+    // Taken from doing this in GDScript.
+    let expected = Quaternion::new(-0.072151, 0.176298, -0.072151, 0.979034);
+    assert_eq_approx!(outcome, expected);
+
+    expect_panic(
+        "Attempted spherical cubic interpolation on quaternions that are not normalized.",
+        || {
+            a.spherical_cubic_interpolate(b, pre_a, post_b, 0.5);
+        },
+    );
+}
+
+#[itest]
+fn quaternion_spherical_cubic_interpolate_in_time() {
+    let pre_a = Quaternion::new(-1.0, -1.0, -1.0, -1.0);
+    let a = Quaternion::new(0.0, 0.0, 0.0, 1.0);
+    let b = Quaternion::new(0.0, 1.0, 0.0, 2.0);
+    let post_b = Quaternion::new(2.0, 2.0, 2.0, 2.0);
+
+    let outcome = a.spherical_cubic_interpolate_in_time(
+        b.normalized(),
+        pre_a.normalized(),
+        post_b.normalized(),
+        0.5,
+        0.1,
+        0.1,
+        0.1,
+    );
+    // Taken from doing this in GDScript.
+    let expected = Quaternion::new(0.280511, 0.355936, 0.280511, 0.84613);
+    assert_eq_approx!(outcome, expected);
+
+    expect_panic(
+        "Attempted spherical cubic interpolation in time on Quaternions that are not normalized.",
+        || {
+            a.spherical_cubic_interpolate_in_time(b, pre_a, post_b, 0.5, 0.1, 0.1, 0.1);
+        },
+    );
+}
 // TODO more tests